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  • 101
    Publikationsdatum: 2023-12-07
    Beschreibung: The ORCID is an open alphanumeric identifier used to uniquely identify researchers.In an increasingly connected scientific landscape, the growing number of published research outputs (data, text, software) and new open publishing models pose major challenges for scientific publication management. The repositories available to FID GEO, GEO-LEOe-docs (SUB Goettingen) and GFZ Data Services (GFZ), have long been working with PIDs such as the Digital Object Identifier (DOI ) and the Open Researcher and Contributor iD (ORCID iD ), and recommend the use of the ORCID. This publication is a translation of the FID GEO article in 〈a href="http://doi.org/10.23689/fidgeo-5832"〉GMIT 87.〈/a〉
    Beschreibung: DFG, SUB Göttingen, GFZ Potsdam
    Beschreibung: research
    Schlagwort(e): ddc:550 ; GMIT
    Sprache: Englisch
    Materialart: doc-type:article , publishedVersion
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  • 102
    Publikationsdatum: 2023-12-19
    Beschreibung: Predicting cirrus cloud properties with confidence requires a sound understanding of the relative roles of homogeneous and heterogeneous ice formation. This study explores the effect of mineral dust and contrail‐processed aviation soot particles as ice‐nucleating particles (INPs) competing with liquid solution droplets in cirrus formation. We study aerosol‐cirrus interactions by accounting for atmospheric variability in updraft speeds and INP number concentrations. Our results confirm the dominant role of mineral dust in ice nucleation events in cirrus clouds. In addition, we show that pre‐existing thin cirrus may suppress ice formation when updraft speeds are low. We find that homogeneous freezing of liquid solution droplets dominates clear‐sky aerosol‐cirrus interaction above a threshold updraft speed determined by total number concentrations and ice nucleation abilities of INPs. When mineral dust particles exceed number concentrations of 10 L〈sup〉−1〈/sup〉, they reduce homogeneously nucleated ice crystal numbers significantly and even prevent homogeneous freezing for frequently observed local updraft speeds between 10 and 20 cm s〈sup〉−1〈/sup〉. When both mineral dust and aviation soot particles coexist with solution droplets, dust typically prevents ice nucleation by aviation soot. Aviation soot exerts a notable impact on cirrus ice numbers only if updrafts are weak, large soot particles are present in number concentrations that are considerably higher than typically observed in emission measurements, and/or number concentrations of mineral dust and other INPs are low. Overall, our results elucidate the role of aviation soot‐cirrus interactions in the presence of other INP types.
    Beschreibung: Plain Language Summary: Understanding ice formation from atmospheric aerosol particles in cirrus clouds is important to correctly predict the impact of cirrus on climate. Here, we study for the first time on the process level cirrus ice formation from freezing of liquid solution droplets in competition with ice nucleation on mineral dust and aviation‐produced soot particles. Our results show that in the majority of cloud‐forming updrafts, mineral dust particles dominate cirrus formation over droplet freezing and that they outcompete aviation soot in producing cloud ice. Moreover, already existing cirrus clouds often prevent ice formation from these particle types altogether. Our results help evaluate cirrus parameterizations within global models and constrain model‐based estimates of the global climate impact of aviation.
    Beschreibung: Key Points: Mineral dust outcompetes contrail‐processed aviation soot in aerosol‐cirrus interactions. Mineral dust reduces homogeneously nucleated ice crystal numbers more effectively than aviation soot. Strong potential of pre‐existing cirrus clouds to suppress new cloud ice formation.
    Beschreibung: European Commission http://dx.doi.org/10.13039/501100000780
    Beschreibung: https://doi.org/10.5281/zenodo.7404707
    Schlagwort(e): ddc:551.5 ; ice nucleating particles ; cirrus ; aerosol cloud interactions
    Sprache: Englisch
    Materialart: doc-type:article
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  • 103
    Publikationsdatum: 2023-12-19
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The MErcury Radiometer and Thermal Infrared Spectrometer instrument onboard the BepiColombo spacecraft is designed to investigate Mercury’s surface in the mid‐infrared (mid‐IR). Based on MESSENGER data and modeling, Mercury is thought to be evolved under highly reducing conditions (e.g., McCubbin et al., 2017, 〈ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1002/2017JE005367"〉https://doi.org/10.1002/2017JE005367〈/ext-link〉; Namur & Charlier, 2017, 〈ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1038/ngeo2860"〉https://doi.org/10.1038/ngeo2860〈/ext-link〉). The modeling also indicates that Mercury's surface is rich in feldspar. However, it is unknown if reducing conditions during the emplacement of volcanic melts have an influence on the IR properties of feldspars. Therefore, we investigated basaltic samples from the Bühl quarry in northern Hesse, Germany, that evolved under reducing conditions in the mid‐IR and compared the spectra with samples that experienced more oxidizing conditions during their formation. The Bühl samples are feldspar‐rich and contain metallic iron in some areas. Our investigations show that there are no differences between feldspars that formed under different oxidizing conditions. All spectral properties could be explained by well‐known factors that affect mid‐IR spectra of silicates.〈/p〉
    Beschreibung: Plain Language Summary: ESA's and Japan Aerospace Exploration Agency’s spacecraft BepiColombo is equipped, beside other instruments, with a thermal infrared (IR) radiometer and spectrometer called MErcury Radiometer and Thermal Infrared Spectrometer (MERTIS). For the accurate interpretation of the data from the MERTIS instrument, laboratory analog material is necessary. This analog material must fulfill different characteristics, such as different chemical and mineralogical compositions. Another not yet studied property is the availability of oxygen during the formation of the minerals. Depending on how much oxygen is available, different minerals form. However, this is an important feature, because Mercury is thought to have evolved under highly reducing conditions, as opposed to Earth where nearly all material formed significant more oxidizing conditions. One phase that is strongly associated with reducing magma formation conditions is metallic iron. There are only few natural outcrops on Earth, were stronger reducing conditions were present so that metallic iron could be formed. One of these outcrops is the Bühl quarry in northern Hesse, Germany. From there we used different samples to analyze the effect of oxygen availability on mid‐IR spectra of plagioclase feldspars.〈/p〉
    Beschreibung: Key Points: 〈list list-type="bullet"〉 〈list-item〉 〈p xml:lang="en"〉We present infrared spectra of basaltic samples from the Bühl, Hesse, Germany in preparation of the MERTIS experiment〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Comparison of feldspars formed at different oxygen fugacities showed no spectral differences〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉This is an important result for MERTIS, which will investigate Mercury that formed under reducing conditions〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Beschreibung: DLR
    Beschreibung: http://bc-mertis-pi.uni-muenster.de/
    Schlagwort(e): ddc:549 ; infrared reflectance spectroscopy ; feldspars ; Bühl basalt ; reducing conditions ; Mercury ; MERTIS
    Sprache: Englisch
    Materialart: doc-type:article
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  • 104
    Publikationsdatum: 2023-12-19
    Beschreibung: In this study, we investigate whether a better representation of precipitation in the Amazon basin arises through an explicit representation of convection and whether it is related to the representation of organized systems. In addition to satellite data, we use ensemble simulations of the ICON‐NWP model at storm‐resolving (2.5–5.0 km) scales with explicit convection (E‐CON) and coarse resolutions, with parameterized convection (P‐CON). The main improvements in the representation of Amazon precipitation by E‐CON are in the distribution of precipitation intensity and the spatial distribution in the diurnal cycle. By isolating precipitation from organized convective systems (OCS), it is shown that many of the well simulated precipitation features in the Amazon arise from the distribution of these systems. The simulated and observed OCS are classified into 6 clusters which distinguish nocturnal and diurnal OCS. While the E‐CON ensembles capture the OCS, especially their diurnal cycle, their frequency is reduced compared to observations. Diurnal clusters are influenced by surface processes such as cold pools, which aid to the propagation of OCS. Nocturnal clusters are rather associated with strong low‐level easterlies, possibly related to the Amazonian low‐level jet. Our results also show no systematic improvement with a twofold grid refinement and remaining biases related to stratiform features of OCS suggest that yet unresolved processes play an important role for correctly representing precipitating systems in the Amazon.
    Beschreibung: Plain Language Summary: The Amazon basin is a relevant element of the Earth system because it influences the global water and carbon cycle, as well as it constitutes a unique ecosystem. Over this important region, conventional climate models do not simulate basic features of rainfall given their inability to resolve this physical process due to their coarse spatial resolution. In this study, we use high‐resolution simulations that allow an explicit representation of such physical process (moist convection) and compare them with a set of coarse‐resolution simulations and observed precipitation. We find that improvements in the representation of Amazon rainfall, such as the distribution of light and high intensity rain rates, as well as the spatial variability of the diurnal cycle, are explained by the explicit representation of moist convection. Moreover, these improvements arise from the representation of big and organized systems that produce intense rainfall (OCS). We find that particular environmental conditions are associated with the OCS according to their time of occurrence. Diurnal OCS are mainly influenced by interactions with the surface, while nocturnal OCS are related to strong low‐level winds. Some of the remaining discrepancies with observed OCS do not show improvements when refining the grid by a factor of two.
    Beschreibung: Key Points: An explicit representation of convection enables the emergence of organized systems (OCS) leading to improved simulations of Amazon rainfall. Propagating cold‐pools and strong low‐level easterlies are related to the occurrence of diurnal and nocturnal OCS, respectively. Systematic biases in the size, intensity and nocturnal precipitation phase of OCS are insensitive to a twofold refinement in resolution.
    Beschreibung: Max Planck Society for the Advancement of Science
    Beschreibung: European Horizon 2020 project CONSTRAIN
    Beschreibung: https://www.metoffice.gov.uk/hadobs/hadisst/data/download.html
    Beschreibung: https://www.ncei.noaa.gov/data/cmorph-high-resolution-global-precipitation-estimates/access/30min/8km
    Beschreibung: https://www.hydrosheds.org/products/hydrobasins
    Beschreibung: https://esgf-data.dkrz.de/projects/cmip6-dkrz/
    Beschreibung: https://pure.mpg.de/
    Schlagwort(e): ddc:551.6 ; Amazon rainfall ; organized precipitating systems ; storm‐resolving simulation
    Sprache: Englisch
    Materialart: doc-type:article
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  • 105
    Publikationsdatum: 2023-12-19
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉We monitored stable water isotopes in liquid precipitation and atmospheric water vapour (δ〈sub〉v〈/sub〉) using in situ cavity ring‐down spectroscopy (CRDS) over a 2 month period in an urban green space area in Berlin, Germany. Our aim was to better understand the origins of atmospheric moisture and its link to water partitioning under contrasting urban vegetation. δ〈sub〉v〈/sub〉 was monitored at multiple heights (0.15, 2 and 10 m) in grassland and forest plots. The isotopic composition of δ〈sub〉v〈/sub〉 above both land uses was highly dynamic and positively correlated with that of rainfall indicating the changing sources of atmospheric moisture. Further, the isotopic composition of δ〈sub〉v〈/sub〉 was similar across most heights of the 10 m profiles and between the two plots indicating high aerodynamic mixing. Only at the surface at ~0.15 m height above the grassland δ〈sub〉v〈/sub〉 showed significant differences, with more enrichment in heavy isotopes indicative of evaporative fractionation especially after rainfall events. Further, disequilibrium between δ〈sub〉v〈/sub〉 and precipitation composition was evident during and right after rainfall events with more positive values (i.e., values of vapour higher than precipitation) in summer and negative values in winter, which probably results from higher evapotranspiration and more convective precipitation events in summer. Our work showed that it is technically feasible to produce continuous, longer‐term data on δ〈sub〉v〈/sub〉 isotope composition in urban areas from in situ monitoring using CRDS, providing new insights into water cycling and partitioning across the critical zone of an urban green space in Central Europe. Such data have the potential to better constrain the isotopic interface between the atmosphere and the land surface and to thus, improve ecohydrological models that can resolve evapotranspiration fluxes.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉In situ measurements of urban atmospheric water isotopes (δ〈sub〉v〈/sub〉) at different heights produce reliable and stable high‐resolution data. Urban atmospheric vapour is influenced by varying drivers depending on the type of green space. δ〈sub〉v〈/sub〉 above grassland and tree stands was similar at 10 m height, but near‐surface δ〈sub〉v〈/sub〉 indicated higher evaporation and vapour enrichment over grass. We detected occasional dis‐equilibrium between vapour and precipitation isotopes.〈boxed-text position="anchor" content-type="graphic" id="hyp14989-blkfxd-0001" xml:lang="en"〉 〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:08856087:media:hyp14989:hyp14989-toc-0001"〉 〈/graphic〉 〈/boxed-text〉〈/p〉
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Einstein Stiftung Berlin http://dx.doi.org/10.13039/501100006188
    Beschreibung: Leverhulme Trust http://dx.doi.org/10.13039/501100000275
    Beschreibung: German Research Foundation http://dx.doi.org/10.13039/501100001659
    Beschreibung: Einstein Research Unit
    Beschreibung: Einstein Foundation Berlin and Berlin University Alliance
    Beschreibung: BiNatur
    Beschreibung: BMBF http://dx.doi.org/10.13039/501100002347
    Beschreibung: Leverhulme Trust through the ISO‐LAND project
    Schlagwort(e): ddc:551.6 ; atmospheric vapour isotopes ; cities ; ecohydrology ; equilibrium assumption ; in situ monitoring ; urban green spaces
    Sprache: Englisch
    Materialart: doc-type:article
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  • 106
    facet.materialart.
    Unbekannt
    ARGE GMIT, Bonn
    Publikationsdatum: 2024-01-04
    Beschreibung: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom September 2023 enthält die Themenblöcke: GEOfokus: Dimensionierung und Betrieb von Erdwärmesonden, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Beschreibung: journal
    Schlagwort(e): ddc:550 ; GMIT
    Sprache: Deutsch
    Materialart: doc-type:book , publishedVersion
    Format: 120
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  • 107
    Publikationsdatum: 2024-01-12
    Beschreibung: A split‐and‐delay unit for the extreme ultraviolet and soft X‐ray spectral regions has been built which enables time‐resolved experiments at beamlines FL23 and FL24 at the Free‐electron LASer in Hamburg (FLASH). Geometric wavefront splitting at a sharp edge of a beam splitting mirror is applied to split the incoming soft X‐ray pulse into two beams. Ni and Pt coatings at grazing incidence angles have been chosen in order to cover the whole spectral range of FLASH2 and beyond, up to hν = 1800 eV. In the variable beam path with a grazing incidence angle of ϑd = 1.8°, the total transmission (T) ranges are of the order of 0.48 〈 T 〈 0.84 for hν 〈 100 eV and T 〉 0.50 for 100 eV 〈 hν 〈 650 eV with the Ni coating, and T 〉 0.06 for hν 〈 1800 eV for the Pt coating. For a fixed beam path with a grazing incidence angle of ϑf = 1.3°, a transmission of T 〉 0.61 with the Ni coating and T 〉 0.23 with a Pt coating is achieved. Soft X‐ray pump/soft X‐ray probe experiments are possible within a delay range of −5 ps 〈 Δt 〈 +18 ps with a nominal time resolution of tr = 66 as and a measured timing jitter of tj = 121 ± 2 as. First experiments with the split‐and‐delay unit determined the averaged coherence time of FLASH2 to be τc = 1.75 fs at λ = 8 nm, measured at a purposely reduced coherence of the free‐electron laser.
    Beschreibung: The properties of the recently installed split‐and‐delay unit at beamlines FL23 and FL24 at FLASH2 are presented. Its operational range, performance parameters and results of a first experiment are described. image
    Schlagwort(e): ddc:550.724 ; time‐resolved pump–probe ; XUV ; soft X‐rays ; free‐electron laser
    Sprache: Englisch
    Materialart: doc-type:article
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  • 108
    Publikationsdatum: 2024-01-12
    Beschreibung: This paper develops a depth‐averaged theory to investigate submarine landslides and resulting water waves. The problems here consist of a pure fluid regime and a mixture regime of grains and fluid. Both regimes separate from one another by an interface, which is a material surface for grains. While the downslope velocities of the both phases are assumed to be identical in the mixture regime, the velocity shear causes a rearrangement of grains, which induces a vertical relative motion between the phases. The established theory consists of five coupled conservation equations, which describe the evolution of the pure fluid thickness, the mixture thickness, the solids volume fraction, and depth‐averaged velocities. To handle nonconservative products emerging in the equations, a new coordinate system is introduced to rewrite the equation system in an equivalent form, so that numerical solutions are insensitive to the choice of discretization of nonconservative products, which enables us to accurately characterize the dynamic behaviors of particles in the collapse experiments of underwater particles and describe free‐surface wave profiles. It is shown that the computed results are in good agreement with the experiments reported in previous literatures.
    Beschreibung: Plain Language Summary: Developing an accurate and rigorous model to describe the motion of submarine landslides and the evolution of the induced water wave remains a challenge to date. Existing models usually simplify the submarine mass as a sling box or a deformable rheological material which is unable to interpret certain fast‐moving and some slow‐moving granular flows that differ only in their compactness. In this paper, the existing models are improved by taking account of the dilatancy effects of the particles. Numerical results of underwater granular collapse show that the predictions of the temporal evolution of the thickness profiles and the final deposit morphology using the current model are in better agreement with experiments compared to the existing models. The present model also provides a better prediction in the wave profiles induced by submarine landslides, which makes the present theory very promising to investigate natural geophysical flows in the future.
    Beschreibung: Key Points: A depth‐averaged model is presented, which considers excess pore fluid pressure and fluid mass transfer across the avalanche surface. A robust numerical method is used, so that the computed solution is insensitive to the way nonconservative products are discretized. Significant improvements in the prediction of the grain thickness profiles and the free‐surface waves are found compared with existing models.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Fundamental Research Funds for the Central Universities http://dx.doi.org/10.13039/501100012226
    Beschreibung: National Key Research and Development Program of China http://dx.doi.org/10.13039/501100012166
    Beschreibung: https://doi.org/10.48328/tudatalib-931
    Schlagwort(e): ddc:551.3 ; submarine landslides ; granular dilatancy ; depth‐averaged theory ; nonoscillatory central‐upwind scheme ; free surface wave flow
    Sprache: Englisch
    Materialart: doc-type:article
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  • 109
    Publikationsdatum: 2024-01-12
    Beschreibung: Thematic map creation is a meticulous process that requires several steps to be accomplished regardless of the type of map to be produced, from data collection, through data exploitation and map publication in print, image, and GIS format. Examples are geolithological, and geomorphological maps in which most of the highest time‐consuming tasks are those related to the discretization of single objects. Introducing also interpretative biases because of the different experience of the mappers in identifying a set of unique characteristics that describe those objects. In this setting, Deep Learning Computer Vision techniques could play a key role but lack the availability of a complete set of tools specific for planetary mapping. The aim of this work is to develop a comprehensive set of ready‐to‐use tools for landforms mapping based on validated Deep Learning methodologies and open‐source libraries. We present DeepLandforms, the first pre‐release of a toolset for landform mapping using Deep Learning that includes all the components for data set preparation, model training, monitoring, and inference. In DeepLandforms, users have full access to the workflow and control over all the processes involved, granting complete control and customization capabilities. In order to validate the applicability of our tool, in this work we present the results achieved using DeepLandforms in the science case of mapping sinkhole‐like landforms on Mars, as a first example that can lead us into multiple and diverse future applications.
    Beschreibung: Plain Language Summary: The creation of maps is a complex set of several tasks that, regardless of the type of map, are often very time‐consuming. For instance, all the occurrences of a specific object, natural or man‐made in a defined area, need to be identified, drawn and classified manually. Mapping large objects in small areas is an easy task but may be unmanageable in cases such as small landforms on the entire surface of a planet. Nowadays, especially on Earth, researchers and professionals take advantages of highly specialized software based on a technique called Deep Learning. Such software are almost never free nor ready‐to‐use and often requires higher knowledge in computer programming languages. In this work, we present the first pre‐release of a novel open‐source computer software, nearly ready‐to‐use, that provides all the instruments for approaching Deep Learning for automatic landforms mapping. We present also the results obtained by trying this software using data of Mars's surface to map sinkhole‐like landforms.
    Beschreibung: Key Points: Instance Segmentation methodology is used to map landforms obtaining vectorial data in geopackage file format. A newly developed composite toolset to perform image pre‐processing, data labeling, model training and inference tasks is presented. The results of a prime case of mapping pit and skylights on Mars surface are showed.
    Beschreibung: European Union's Horizon 2020 research and innovation programme
    Beschreibung: https://doi.org/10.5281/zenodo.7351391
    Beschreibung: https://doi.org/10.5281/zenodo.7488867
    Beschreibung: https://ode.rsl.wustl.edu/odeholdings/Mars_holdings.html
    Schlagwort(e): ddc:523 ; mapping ; Mars ; pits ; skylight ; deep learning ; toolset
    Sprache: Englisch
    Materialart: doc-type:article
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  • 110
    Publikationsdatum: 2024-01-12
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉〈italic〉XDSGUI〈/italic〉 is a lightweight graphical user interface (GUI) for the 〈italic〉XDS〈/italic〉, 〈italic〉SHELX〈/italic〉 and 〈italic〉ARCIMBOLDO〈/italic〉 program packages that serves both novice and experienced users in obtaining optimal processing and phasing results for X‐ray, neutron and electron diffraction data. The design of the program enables data processing and phasing without command line usage, and supports advanced command flows in a simple user‐modifiable and user‐extensible way. The GUI supplies graphical information based on the tabular log output of the programs, which is more intuitive, comprehensible and efficient than text output can be.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉A customizable stateless graphical user interface simplifies the processing, analysis and phasing of diffraction data.〈boxed-text position="anchor" content-type="graphic" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:16005767:jcr2yr5110:jcr2yr5110-fig-0001"〉 〈alt-text〉image〈/alt-text〉 〈/graphic〉〈/boxed-text〉〈/p〉
    Schlagwort(e): ddc:548 ; X‐ray diffraction ; neutron diffraction ; electron diffraction ; data processing ; graphical user interfaces ; phasing ; XDS ; ARCIMBOLDO ; SHELX
    Sprache: Englisch
    Materialart: doc-type:article
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  • 111
    Publikationsdatum: 2023-02-28
    Beschreibung: Im Albvorsprung südlich Regensburg liegen zwischen Störungen der mesozoischen Schichttafel schmale Becken. Während deren Bildung setzte sich ein klastischer Sedimentkomplex in den expandierenden Becken ab, der in das obere Untermiozän-untere Mittelmiozän gestellt wird und in konkav aufgebogener Lagerungsform vorliegt. Die Diskordanz an der Basis der überlagernden Sand- und Geröllschichten wird dem Mittelmiozän zugerechnet und zeigt den Abschluß der tektonischen Beckenbildung. Es wird angenommen, dass die Verbiegung des nach 150° tauchenden, älteren Hemauer Sattels ein Spannungsfeld verursachte und damit senkrecht zu dessen Achse orientierte Dehnungsbrüche und ein konjugiertes Scherkluftsystem erzeugte. Dadurch kam es vermutlich zu den extensionalen Beckenbildungen, deren Längsachsen an den Maxima der Kluftrichtungen und Bruchflächen orientiert waren. Dieses System wurde von der in Mitteleuropa heute ~140° streichenden horizontalen Schubspannung (Prinz & Strauss 2018) überlagert. Darüber hinaus können beide von Peterek et al. (1997) über Paläostress-Analysen für den Zeitraum des (beginnenden) Neogens dargestellten Extensionsregimes zur Erklärung der tektonischen Beckenbildungen im hier untersuchten Gebiet beitragen. Die Ergebnisse stellen Grundlagen für Baugrunduntersuchungen im Bereich Regensburg-Süd und Bad Abbach dar.
    Beschreibung: research
    Schlagwort(e): ddc:550 ; Miozäne Dehnungsbecken ; Tertiär ; Regensburg-Süd ; Bad Abbach
    Sprache: Deutsch
    Materialart: doc-type:article
    Format: 19
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  • 112
    Publikationsdatum: 2023-03-21
    Beschreibung: DFG
    Beschreibung: Bei bodenkundlichen und geologischen Untersuchungen werden ground-penetrating radar (GPR)-Reflexionsdaten routinemäßig zur Erkundung des oberflächennahen Untergrundes verwendet. Da Torfgebiete einen wichtigen Teil des globalen Klimasystems darstellen, besteht ein zunehmendes Interesse daran, Torfablagerungen detaillierter zu untersuchen und zu charakterisieren. Bis heute konzentriert sich die Anwendung von GPR in Mooren auf die Erfassung von 2D Daten entlang ausgewählter Profile, häufig mit dem Ziel, Modelle der Torfmächtigkeit und -stratigraphie abzuleiten. Wir stellen eine 3D GPR-Fallstudie aus einem Moorgebiet im Nordosten Deutschlands vor, in welcher wir unter Verwendung moderner Aufzeichnungs-, Bearbeitungs- und Interpretationsstrategien ein detailliertes 3D Modell des untersuchten Torfkörpers entwickeln. Unsere Ergebnisse zeigen erhebliche Schwankungen in der Torfmächtigkeit einschließlich einer markanten, kreisförmigen Vertiefungsstruktur. Wir kommen zu dem Schluss, dass solche Strukturen mittels 2D GPR-Aufzeichnungsstrategien nicht zuverlässig hätten abgebildet werden können. Somit unterstreichen unsere Ergebnisse den Nutzen von 3D GPRStrategien, um ein tieferes Verständnis von Torfablagerungen und ihren Eigenschaften zu etablieren.
    Beschreibung: poster
    Sprache: Deutsch
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  • 113
    Publikationsdatum: 2023-03-21
    Beschreibung: Two mysterious moons whirl around Mars. Despite the many missions to the planet, not a single one has focused on its satellites — or, rather, not a single successful one. Three previous Martian moon explorers, launched by Russia or the Soviet Union, all failed. Now Japan is trying its luck with a high-risk venture that aims to grab rocks from the larger Martian moon and bring them to Earth for laboratory analysis. “It’s a very scary mission,” says Tomohiro Usui of the Japan Aerospace Exploration Agency (JAXA) in Sagamihara. The spacecraft’s daunting tasks will include multiple touchdowns on a heavily cratered world. The chief goal is to settle a debate over the origin of the moons (1). Did the Red Planet steal them from the asteroid belt, or did they form after an asteroid smashed into Mars? The answer carries implications for satellites elsewhere and perhaps even for the origin of water on Earth.
    Beschreibung: report
    Schlagwort(e): ddc:520 ; Mars ; Monde ; moons
    Sprache: Englisch
    Materialart: doc-type:article , publishedVersion
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  • 114
    Publikationsdatum: 2023-03-21
    Beschreibung: Gas exchange between the atmosphere and ocean interior profoundly impacts global climate and biogeochemistry. However, our understanding of the relevant physical processes remains limited by a scarcity of direct observations. Dissolved noble gases in the deep ocean are powerful tracers of physical air-sea interaction due to their chemical and biological inertness, yet their isotope ratios have remained underexplored. Here, we present high-precision noble gas isotope and elemental ratios from the deep North Atlantic (~32°N, 64°W) to evaluate gas exchange parameterizations using an ocean circulation model. The unprecedented precision of these data reveal deep-ocean undersaturation of heavy noble gases and isotopes resulting from cooling-driven air-to-sea gas transport associated with deep convection in the northern high lati-tudes. Our data also imply an underappreciated and large role for bubble-mediated gas exchange in the global air-sea transfer of sparingly soluble gases, including O2, N2, and SF6. Using noble gases to validate the physical representation of air-sea gas exchange in a model also provides a unique opportunity to distinguish physical from biogeochemical signals. As a case study, we compare dissolved N2/Ar measurements in the deep North Atlantic to physics-only model predictions, revealing excess N2 from benthic denitrification in older deep waters (below 2.9 km). These data indicate that the rate of fixed N removal in the deep Northeastern Atlantic is at least three times higher than the global deep-ocean mean, suggesting tight coupling with organic carbon export and raising potential future implications for the marine N cycle.
    Beschreibung: NSF, UK NERC, University of Oxford Advanced Research Computing facility
    Beschreibung: https://www.bco-dmo.org/project/887496
    Beschreibung: research
    Schlagwort(e): ddc:551 ; gas exchange ; nitrogen cycle ; overturning circulation ; air-sea interaction ; noble gases
    Sprache: Englisch
    Materialart: doc-type:article , publishedVersion
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  • 115
    Publikationsdatum: 2023-03-20
    Beschreibung: Geophysical sensing methods such as magnetics, electromagnetics and ground penetrating radar are the essential methods for the detection of unexploded ordnances (UXO) in the subsurface. Apart from a precise localization of buried ammunition remnants, a reliable discrimination of anomaly signatures caused by UXO and Non-UXO bodies is one of the currently most challenging tasks in the field of explosive ordnance clearance. Therefore, we exploit different phase-based edge detectors to evaluate their applicability for improving the detection performance and especially for distinguishing buried objects by the anomaly signature they cause. In the present poster, we apply our new approach on synthetic magnetic data for spherical and elliptical object geometries. Furthermore, we compare the synthetic cases to real magnetic survey data collected from a test site at SENSYS GmbH in Bad Saarow.
    Beschreibung: poster
    Schlagwort(e): edge detection ; UXO ; magnetics
    Sprache: Englisch
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  • 116
    Publikationsdatum: 2023-03-15
    Beschreibung: Sea level rise caused by climate change represents a challenge to coastal flood protection measures, particularly in regions such as the federal state of Schleswig-Holstein. Large parts along the North Sea coast are protected by dikes and offshore islands provide additional shelter to the hinterland, which often lies just above or even beneath sea level. We have examined InSAR time series data from the German Ground Motion Service along the entire west coast dike route from the Danish border to Wedel. We want to estimate how these data can be used to detect and monitor ground motion processes related to dikes, especially in cases where PS (persistent scatterer) are irregularly distributed. We found, that mainly those parts of the dikes can be monitored by PS interferometry where the seaward dike base is shielded by heavy armourstone acting as sufficient back-scatters for radar waves. Here, ground motion processes induced by additional load of reinforcing construction work can be observed. In some regions the dikes are influenced by long-term, large-scale subsidence. We performed statistical analysis on low pass filtered PS time series to automatically identify significant ground motion and/or ground motion events within a local area of interest. Preliminary results suggest, that we may be able to identify dike segments which show signs of anomalous ground motion and thus should be monitored closely.
    Beschreibung: poster
    Schlagwort(e): InSAR ; Ground motion ; Schleswig-Holstein ; Dike ; Geophysik
    Sprache: Englisch
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  • 117
    Publikationsdatum: 2023-03-14
    Beschreibung: Providing measurements for scientific simulation software often requires tedious manual preprocessing of data sets. To overcome this problem and make it easy for simulation tools to access heterogeneous data sets directly, we have developed the Ice Data Hub. The Ice Data Hub combines available data from Earth or other planetary bodies including their meta data and allows it to be displayed, interpreted and exported. Most important is its functionality as an interface between data and simulation tools. For example, we develop models for thermodynamic melting processes that can evaluate measured data directly thanks to the Ice Data Hub. It can also be used as a black box, where a simulation tool queries the Hub to provide a property. This could, for example, be a material property at a certain depth. The accessing functionality for the user is wrapped in the sense that the user uses similar routines, regardless the format of data, e.g., analytical expression, look-up table or interpolant. To illustrate the capabilities of the Ice Data Hub, we show results of 1) thermal conductivity simulations in glacial ice with temperature data from Langenferner Glacier, Italy, and 2) trajectory models of ice melting probes compared with housekeeping data from field experiments at Taylor Glacier, Antarctica. 1) The observed temperature evolution from a measured time series of 1D temperature observations in an interval of one hour differs from the theoretically predicted temperature evolution, which was determined on the basis of an idealised seasonal and diurnal temperature variation at the surface and constant ice material parameters. Hence, we reconstruct spatio-temporally varying effective material parameters from these observations using the Crank Nicolson Method. 2) Ice melting probes are developed to penetrate ice and access potential subglacial water reservoirs for insitu studies. The ice-sheet transit provides an excellent opportunity to study the structure and composition of the ice itself using geophysical and other in-situ measurements. Both housekeeping data and scientific sensors of the ice melting probe can be used to derive ice properties and analyse it with various tools via the Ice Data Hub. The Ice Data Hub facilitates the functionality needed to make data repositories of different format simulationready and guarantee reproducibility of data-integrated simulations. It is planned to make the Ice Data Hub available as open source software in the near future.
    Beschreibung: poster
    Sprache: Englisch
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  • 118
    Publikationsdatum: 2023-02-03
    Beschreibung: Diese Bergordnung wurde am 22. Juli 1468 für die Bergwerke in Schwaz von Herzog Siegmund von Österreich erlassen. In der Einleitung der Bergordnung bemerkte Herzog Siegmund, dass es trotz zweier von ihm verfasster Briefe zum Schwazer Bergbau dort zu Unstimmigkeiten gekommen war. Gemeinsam mit Gewerken und Räten aus Schwaz und Gossensaß, wurde eine neue Bergordnung erstellt. In 14 Artikeln wurden die Zuständigkeiten der Hutleute und Bergrichter dargelegt sowie die Bezahlung der Bergleute geregelt. Explizit wurden nochmals das Vorgehen bei einer korrekten Grubenvermessung beschrieben. Auch wurde der Erzverkauf außerhalb von Schwaz und Gossensaß verboten.
    Beschreibung: source
    Schlagwort(e): Herzog Siegmund von Österreich ; Österreich ; Tirol ; Schwaz ; Gossensaß ; Silberbergbau ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 6
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  • 119
    facet.materialart.
    Unbekannt
    Publikationsdatum: 2023-02-03
    Beschreibung: Der Name Angulatensandstein bezieht sich auf den Ammonit Schlotheimia angulata (Schlotheim) im tieferen Unterjura in der Bamberg- Formation (Hettangium). Der Sandstein aber fällt in Franken nur in seinem höchsten Teil mit der Angulata-Biozone zusammen. Die tieferen Teile liegen in den Liasicus- und Planorbis-Zonen, dazu tritt er im Osten auch in der fluviatilen Bayreuth-Formation auf. Damit ist der Name Angulatensandstein nicht richtig und revisionsbedürftig. Da eine Subformation der Bamberg-Formation, nämlich die Forchheim-Subformation, die wesentlich aus diesem feinkörnigen Sandstein besteht, nach der Stadt Forchheim/Oberfranken benannt wurde, lag es nahe, den Sandstein als Forchheim-Sandstein zu bezeichnen.
    Beschreibung: research
    Schlagwort(e): Unterjura ; Bamberg-Formation ; fluviatile Fazies ; marine Fazies ; Schlotheimia angulata
    Sprache: Deutsch
    Materialart: doc-type:article , acceptedVersion
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  • 120
    Publikationsdatum: 2023-02-05
    Beschreibung: Im Rahmen einer Langzeituntersuchung zur Hochmoorrenaturierung wurden mit umfassenden Daten aus den Jahren von 1984 bis 2021 die Entwicklungen von Wasserhaushalt, Boden, Klima, Nährstoffdynamik, Flora, Vegetation und Fauna untersucht. Im Jahr 1984 wurden Hochmoorpflanzenarten mit Erfolg eingebracht. Bultbildende Torfmoose haben sich nur sehr kleinflächig vor allem in Heideflächen etabliert. Eine flächige Ausbreitung von Schlenkentorfmoosen, Entwicklung von Akrotelm und Streuauflage verringerten die Verdunstung der Fläche, so dass lange Trockenphasen wie 2018/2019 von der Moorvegetation gut überstanden wurden. Feuchteliebende Arthropoden der Moore wurden nachgewiesen, aber nur wenige Hochmoorspezialisten. Ein winterlicher Überstau von 10 – 30 cm für Schlenkenbereiche ist ausreichend. Die Böden wiesen größtenteils abnehmende Gehalte an pflanzenverfügbaren Nährstoffen auf. Unsere Ergebnisse zeigen, dass sich ein teilabgetorftes Hochmoor mit einer Restschicht aus stark zersetztem Hochmoortorf (Schwarztorf) wiedervernässen lässt und dass eine erste Akrotelmentwicklung stattfinden kann. Auch bei einem moderaten weiteren Temperaturanstieg dürften die klimatischen Bedingungen für die Hochmoorregeneration in Nordwestdeutschland ausreichen.
    Beschreibung: As part of a long-term study on raised bog restoration, we used comprehensive data covering the period from 1984 to 2021 to investigate developments in water balance, soil, climate, nutrient dynamics, flora, vegetation and fauna. In 1984, raised bog plant species were introduced successfully. Hummock Sphagnum species established mainly in heath areas on a very small scale. The areal spread of hollow Sphagnum species, development of acrotelm and litter overlay reduced evaporation from the area, so that long dry periods such as 2018/19 were well survived by the bog vegetation. Several hygrophilic mire invertebrate species were recorded, but only few raised bog specialists. Winter inundation of about 10 to 30 cm for areas with hollow Sphagnum species is sufficient. The soils exhibited decreasing contents of plant-available nutrients. Our results show that a partially cutover raised bog with a residual layer of highly decomposed raised bog peat (black peat) can be rewetted and initial acrotelm development can occur. Even with a moderate further temperature increase, the climatic conditions should be sufficient for raised bog regeneration in northwest Germany.
    Beschreibung: Das Projekt wurde als Erprobungs- und Entwicklungsvorhaben (E+E-Vorhaben) „Wissenschaftlichen Nachuntersuchung 2018-2021 des E+E-Vorhabens “Leegmoor” (1984-1996) - Universität Bremen“ (Förderkennzeichen: 3518892005) durch das Bundesamt für Naturschutz (BfN) mit Mitteln des Bundesministeriums für Umwelt, Naturschutz und nukleare Sicherheit (BMU) gefördert.
    Beschreibung: research
    Schlagwort(e): Langzeituntersuchung ; Hochmoorrenaturierung ; Wiedervernässung ; Beimpfung ; Torfmoos ; Klimawandel ; Acrotelm-Bildung
    Sprache: Deutsch
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  • 121
    facet.materialart.
    Unbekannt
    Publikationsdatum: 2023-02-11
    Beschreibung: Am 24. Juli 1494 erließ Herzog Georg von Sachsen einen Zusatz zu der bereits bestehenden Bergordnung für die Bergwerke in Altenberg und Geising vom 25. Juli 1491. In acht Paragrafen wurde nochmals die pünktliche Lohnzahlung angemahnt sowie die explizit arbeitsfreien Feiertage benannt. Weiterhin wurde die Qualitätskontrolle der Zwitter angeordnet und ein Verkaufsverbot für Zwitter und Zinn durch die Bergleute erlassen. Veröffentlicht wurde der Zusatz hier als Anhang an die am 1. Januar 1492 erlassene Version der Bergordnung vom 25. Juli 1491. Die Änderungen zwischen dieser Bergordnung und der ursprünglichen Bergordnung vom 25. Juli 1491 wurden durch Kursivschrift gekennzeichnet. Die Änderungen enthalten zusätzliche Strafzahlungen, Verbote und Ausnahmen. Den Gewerken wurde beispielsweise gestattet, die Zubuße nicht in 14 Tagen, sondern erst innerhalb von sechs Wochen zu zahlen. Nach Beschwerden der Gewerken wurde auch die Lohnzahlung in Graupen nochmals bis zum Sankt Michaelistag (29. September) 1492 genehmigt.
    Beschreibung: source
    Schlagwort(e): Herzog Georg von Sachsen ; Herzog Albrecht von Sachsen ; Graupen/Krupka ; Altenberg ; Geising ; Zinnbergbau ; Sachsen ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 16
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  • 122
    Publikationsdatum: 2023-06-21
    Beschreibung: Volcanic inflation and deflation often precede eruptions and can lead to seismic velocity changes (dv/v $dv/v$) in the subsurface. Recently, interferometry on the coda of ambient noise‐cross‐correlation functions yielded encouraging results in detecting these changes at active volcanoes. Here, we analyze seismic data recorded at the Klyuchevskoy Volcanic Group in Kamchatka, Russia, between summer of 2015 and summer of 2016 to study signals related to volcanic activity. However, ubiquitous volcanic tremors introduce distortions in the noise wavefield that cause artifacts in the dv/v $dv/v$ estimates masking the impact of physical mechanisms. To avoid such instabilities, we propose a new technique called time‐segmented passive image interferometry. In this technique, we employ a hierarchical clustering algorithm to find periods in which the wavefield can be considered stationary. For these periods, we perform separate noise interferometry studies. To further increase the temporal resolution of our results, we use an AI‐driven approach to find stations with similar dv/v $dv/v$ responses and apply a spatial stack. The impacts of snow load and precipitation dominate the resulting dv/v $dv/v$ time series, as we demonstrate with the help of a simple model. In February 2016, we observe an abrupt velocity drop due to the M7.2 Zhupanov earthquake. Shortly after, we register a gradual velocity increase of about 0.3% at Bezymianny Volcano coinciding with surface deformation observed using remote sensing techniques. We suggest that the inflation of a shallow reservoir related to the beginning of Bezymianny's 2016/2017 eruptive cycle could have caused this local velocity increase and a decorrelation of the correlation function coda.
    Beschreibung: Plain Language Summary: Before eruptions, volcanoes inflate due to the rising magma from below. Previous studies have found that these deformations can lead to small changes in the properties of the surrounding rock. We use passive image interferometry, a method that relies on the omnipresent background vibration of the Earth—mostly induced by the oceans, to measure these changes at the Klyuchevskoy Volcanic Group in Kamchatka, Russia. However, in Kamchatka, this background noise is masked and distorted by small earthquakes and tremors originating from the volcanoes themselves. We combine machine learning techniques with established monitoring methods to find times when these tremors remain similar. Afterward, we use data from these time periods in the conventional way to observe changes in the soil and the rock. Our results show that rain‐ and snowfall and the thickness of the snow cover exert the strongest influence on the properties of the rocks. Additionally, we found that a large magnitude 7.2 earthquake, which struck Kamchatka during our study, caused a slight weakening of the rocks due to microstructural damage. We register changes shortly before an eruption and suggest a connection to the beginning of an eruptive cycle in 2016.
    Beschreibung: Key Points: Fluctuating noise conditions lead to distortions in noise interferometry studies, which we avoid with the help of machine learning. The seismic velocity on Kamchatka is affected by numerous mechanisms, amongst them environmental, tectonic, and volcanic events. We observe a velocity increase at Bezymianny during February 2016 and link it to the beginning of the eruptive cycle.
    Beschreibung: German Research Foundation
    Beschreibung: https://doi.org/10.14470/K47560642124
    Beschreibung: https://doi.org/10.24381/cds.e2161bac
    Beschreibung: https://doi.org/10.5880/GFZ.2.4.2022.002
    Beschreibung: https://doi.org/10.5281/zenodo.7481934
    Schlagwort(e): ddc:551 ; seismology ; volcano monitoring ; machine learning ; ambient noise ; seismic velocity change ; time varying earth structure
    Sprache: Englisch
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  • 123
    Publikationsdatum: 2023-06-21
    Beschreibung: We provide an updated estimate of the annual‐mean, seasonal cycle and interannual variability of the transports and properties of the Weddell Sea Bottom Water (WSBW) plume in the northwestern Weddell Sea. For this we used a densely instrumented mooring array deployed across the continental slope between January 2017 and January 2019. We found that the annual‐mean WSBW transport is 3.4 ± 1.5 Sv, corresponding to a cross‐section area of 35 km2 and a maximum thickness of 203 m. The annual mean transport‐weighted properties of WSBW are −0.99°C (Θ), 34.803 g/kg (SA) and 28.44 kg/m3 (γn). The WSBW is characterized by 3 bottom‐intensified velocity cores, which display seasonal variations in flow speed and transport different varieties of WSBW. The seasonal peak of WSBW transport and density is reached in May (4.7 Sv, 28.443 kg m−3) while the minimum values are observed in February (2.8 Sv, 28.435 kg m−3). The coldest WSBW is found between March and May, and the warmest between August and October. The density decrease of WSBW observed in the austral autumn of 2018 can be explained by warmer ambient waters being entrained during the formation of WSBW. This was enabled by the weakening of the along‐shore winds associated with a positive Southern Annular Mode index, reinforced by a La Niña event in early 2018. The synchronous decrease of total WSBW transport and volume between September 2018 and February 2019 indicates a reduction in the export of the dense precursors of WSBW from the Weddell Sea continental shelf.
    Beschreibung: Plain Language Summary: The Meridional Overturning Circulation (MOC) redistributes heat and carbon dioxide in the world ocean. Thus, it plays an important role in the regulation of our planet's climate. The Weddell Sea is the main contributor to the deep branch of the MOC in the Southern Hemisphere. Despite the importance of this contribution, uncertainties still remain associated to the plume of dense waters transported along the continental slope of the Weddell Sea. To reduce these uncertainties, we analyzed the most densely instrumented mooring array deployed across the continental slope in the northwestern Weddell Sea. We found that this plume flows faster close to the seafloor and that it presents important seasonal and interannual variability. The Weddell Sea Bottom Water interannual variability is influenced by changes in the along‐shore winds driven by the phase of two important climate modes, the Southern Annular Mode and the El Niño‐Southern Oscillation, but also by changes in the export of the dense precursors of WSBW in its formation areas. Increasing our knowledge on the along‐slope plume variability and properties is important to better understand the causes behind the variability of the MOC observed further downstream.
    Beschreibung: Key Points: The Weddell Sea Bottom Water (WSBW) plume presents 3 velocity cores and a clear seasonal cycle, with maximum transports and densities in May and minimum in February. A +SAM, reinforced by a ‐ENSO, favors the warming of WSBW via a wind‐driven warming of the ambient waters entrained during its formation. We observed a marked decrease in WSBW density and transports between September 2018 and February 2019 compared to the previous year.
    Beschreibung: EU Horizon 2020 Research and Innovation Program
    Beschreibung: German Research Foundation
    Beschreibung: Alfred Wegener Institute Helmholtz‐Center
    Beschreibung: https://doi.org/10.5281/zenodo.7500163
    Schlagwort(e): ddc:551.46 ; Weddell Sea ; WSBW ; Meridional Overturning Circulation ; SAM ; ENSO ; deep‐water plume
    Sprache: Englisch
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  • 124
    Publikationsdatum: 2023-06-21
    Beschreibung: Fossil spinicaudatan taxonomy heavily relies on carapace features (size, shape, ornamentation) and palaeontologists have greatly refined methods to study and describe carapace variability. Whether carapace features alone are sufficient for distinguishing between species of a single genus has remained untested. In our study, we tested common palaeontological methods on 481 individuals of the extant Australian genus Ozestheria that have been previously assigned to ten species based on genetic analysis. All species are morphologically distinct based on geometric morphometrics (p ≤ 0.001), but they occupy overlapping regions in Ozestheria morphospace. Linear discriminant analysis of Fourier shape coefficients reaches a mean model performance of 93.8% correctly classified individuals over all possible 45 pairwise species comparisons. This can be further increased by combining the size and shape datasets. Nine of the ten examined species are clearly sexually dimorphic but male and female morphologies strongly overlap within species with little influence on model performance. Ornamentation is commonly species‐diagnostic; seven ornamentation types are distinguished of which six are species‐specific while one is shared by four species. A transformation of main ornamental features (e.g. from punctate to smooth) can occur among closely related species suggesting short evolutionary timescales. Our overall results support the taxonomic value of carapace features, which should also receive greater attention in the taxonomy of extant species. The extensive variation in carapace shape and ornamentation is noteworthy and several species would probably have been assigned to different genera or families if these had been fossils, bearing implications for the systematics of fossil Spinicaudata.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: https://doi.org/10.5061/dryad.fbg79cnxs
    Schlagwort(e): ddc:565 ; clam‐shrimp carapace ; morphometrics ; species delimitation ; Spinicaudata ; Ozestheria ; Australia
    Sprache: Englisch
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  • 125
    Publikationsdatum: 2023-06-21
    Beschreibung: Groundwater abstraction and drainage are considered to be the main drivers for the salinization of low‐lying coastal groundwater systems, while the role of past boundary conditions is less clear. In this study, 3‐D paleo‐hydrogeological variable‐density groundwater flow and salt transport modeling (“paleo‐modeling”) is applied to reconstruct the evolution of groundwater salinities during the Holocene, that is, the last 9,000 years, in Northwestern Germany. Novel aspects of this study include the consideration of highly resolved time‐variant boundary conditions in a 3‐D paleo‐modeling framework, for example, sea‐level rise, surface elevation and coastline changes, development of drainage networks and groundwater abstraction, as well as the quantification of isolated processes impacting salinization. Results show that salinization was a function of sea‐level rise from 9000 BP until 1300 CE. The creation of the dike line ∼1300 CE set the starting point for increasing anthropogenic control of the hydro(geo)logical system: changes in surface elevation and drainage of low‐lying marshes have become main drivers for salinization after 1600 CE when peat was artificially degenerated. Moreover, changes in the dike line caused by storm floods impacted the salinities. Model results for 2020 CE match well with present‐day salinity observations. Yet, salinization will continue in the future, as the hydro(geo)logical system has not reached an equilibrium. The presented paleo‐modeling framework can be viewed as a blueprint for similar low‐lying coastal groundwater systems, influenced by marine transgression and human development. Thereby, it enables the reconstruction of meaningful present‐day salinity distributions, serving as a vital basis for modeling future groundwater systems in a changing climate.
    Beschreibung: Key Points: Salinization of a low‐lying coastal groundwater system during the Holocene, that is, 9000 BP until present‐day, was investigated. Sea‐level rise and the evolution of paleogeography were major controls on groundwater salinization during most of the time. Surface elevation changes due to land cultivation, as well as the development of drainage networks, control salinization since ∼1600 CE.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: https://doi.org/10.5281/zenodo.7633381
    Schlagwort(e): ddc:551.49 ; saltwater intrusion ; variable‐density groundwater flow ; salt transport ; sea‐level rise ; parameter estimation ; iMOD‐WQ
    Sprache: Englisch
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  • 126
    Publikationsdatum: 2023-06-21
    Beschreibung: Measurements of kinetic energy in vortical and divergent fluctuations in the mesosphere and lower thermosphere can be used to study stratified turbulence (ST) and gravity waves. This can be done using horizontal correlation functions of the fluctuating component of velocity. This study introduces a novel method for estimating these correlation functions using radars that observe Doppler shifts of ionized specular meteor trails. The technique solves the correlation functions directly on a longitudinal‐transverse‐up coordinate system, assuming axial symmetry. This procedure is more efficient and leads to smaller uncertainties than a previous approach. The new technique is applied to a year‐long data set from a multistatic specular meteor radar network in Germany, to study the annual variability of kinetic energy within turbulent fluctuations at 87–93 km of altitude. In monthly averages, the kinetic energy is found to be nearly equipartitioned between vortical and divergent modes. Turbulent fluctuations maximize during the winter months with approximately 25% more energy in these months than at other times. The horizontal correlation functions are in agreement with the inertial subrange of ST, exhibiting a 2/3 power law in the horizontal lag direction, with an outermost scale of ST to be about 380 km. This suggests that horizontal correlation functions could be used to estimate turbulent energy transfer rates.
    Beschreibung: Plain Language Summary: Flows exhibit a phenomenon called turbulence, which transfers energy from large scales into smaller scales. This effect is important to quantify the energy budget of the Earth's upper atmosphere. The range of length scales where this phenomenon occurs is called the inertial subrange of turbulence. The classical theory of isotropic turbulence predicts that this energy transfer occurs on length scales smaller than ∼100 m, at 60–110 km altitude. Recent work has shown that horizontal velocity fluctuations can extend the inertial subrange to length scales of up to hundreds of kilometers horizontally. This type of turbulence is called stratified turbulence (ST). So far no comprehensive study has been made to experimentally examine ST in the mesosphere and lower thermosphere (MLT) region on horizontal mesoscales. This study introduces a method for doing so by measuring how the wind fluctuations are correlated as a function of horizontal separation. This is achieved by using meteor radar measurements. The technique is applied to a year‐long data set over Germany. It is found that the MLT wind fluctuations are compatible with ST theory. The introduced method could potentially be used for routinely measuring how kinetic energy flows from large‐scale to small‐scale atmospheric fluctuations.
    Beschreibung: Key Points: A more efficient estimator for horizontal correlation functions is introduced. The rotational and divergent correlation functions of mesosphere and lower thermosphere wind fluctuations are found to be balanced at horizontal mesoscales. Horizontal correlations of wind fluctuations follow a 2/3‐power law for horizontal separations of up to 300–400 km.
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: French Ministry of Foreign and European Affairs
    Beschreibung: Leibniz SAW project FORMOSA
    Schlagwort(e): ddc:551.5 ; mesosphere ; lower thermosphere ; wind fluctuations
    Sprache: Englisch
    Materialart: doc-type:article
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  • 127
    Publikationsdatum: 2023-07-20
    Beschreibung: The seismic activity of a planet can be described by the corner magnitude, events larger than which are extremely unlikely, and the seismic moment rate, the long‐term average of annual seismic moment release. Marsquake S1222a proves large enough to be representative of the global activity of Mars and places observational constraints on the moment rate. The magnitude‐frequency distribution of relevant Marsquakes indicates a $b$‐value of 1.06. The moment rate is likely between $1.55\times {10}^{15}\mathrm{N}\mathrm{m}/\mathrm{a}$ and $1.97\times {10}^{18}\mathrm{N}\mathrm{m}/\mathrm{a}$, with a marginal distribution peaking at $4.9\times {10}^{16}\mathrm{N}\mathrm{m}/\mathrm{a}$. Comparing this with pre‐InSight estimations shows that these tended to overestimate the moment rate, and that 30% or more of the tectonic deformation may occur silently, whereas the seismicity is probably restricted to localized centers rather than spread over the entire planet.
    Beschreibung: Plain Language Summary: The seismic moment rate is a measure for how fast quakes accumulate deformation of the planet's rigid outer layer, the lithosphere. In the past decades, several models for the deformation rate of Mars were developed either from the traces quakes leave on the surface, or from mathematical models of how quickly the planet's interior cools down and shrinks. The large marsquake that occurred on the 4th of May 2022 now allows a statistical estimation of the deformation accumulated on Mars per year, and thus to confront these models with reality. It turns out that, although there is a considerable overlap, the models published prior to InSight tend to overestimate the seismic moment rate, and hence the ongoing deformation on Mars. Possible explanations are that 30% or more of the deformation occurs silently, that is, without causing quakes, or that not the entire planet is seismically active but only specific regions.
    Beschreibung: Key Points: A single large marsquake suffices to constrain the global seismic moment rate. Pre‐InSight estimations tended to overestimate the moment rate. Either a significant part of the ongoing deformation occurs silent, or seismic activity is restricted to some activity centers, or both.
    Beschreibung: Eidgenössische Technische Hochschule Zürich http://dx.doi.org/10.13039/501100003006
    Beschreibung: National Aeronautics and Space Administration http://dx.doi.org/10.13039/100000104
    Beschreibung: UK Space Agency http://dx.doi.org/10.13039/100011690
    Beschreibung: Deutsches Zentrum für Luft‐ und Raumfahrt http://dx.doi.org/10.13039/501100002946
    Beschreibung: Insight SFI Research Centre for Data Analytics http://dx.doi.org/10.13039/501100021525
    Beschreibung: http://dx.doi.org/10.18715/SEIS.INSIGHT.XB_2016
    Beschreibung: http://doi.org/10.17189/1517570
    Schlagwort(e): ddc:523 ; Mars ; InSight ; seismic moment rate ; S1222a
    Sprache: Englisch
    Materialart: doc-type:article
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  • 128
    Publikationsdatum: 2023-07-20
    Beschreibung: A pseudosymmetric description of the crystal lattice derived from a single wide‐angle Kikuchi pattern can have several causes. The small size (〈15%) of the sector covered by an electron backscatter diffraction pattern, the limited precision of the projection centre position and the Kikuchi band definition are crucial. Inherent pseudosymmetries of the crystal lattice and/or structure also pose a challenge in the analysis of Kikuchi patterns. To eliminate experimental errors as much as possible, simulated Kikuchi patterns of 350 phases have been analysed using the software CALM [Nolze et al. (2021). J. Appl. Cryst.54, 1012–1022] in order to estimate the frequency of and reasons for pseudosymmetric crystal lattice descriptions. Misinterpretations occur in particular when the atomic scattering factors of non‐equivalent positions are too similar and reciprocal‐lattice points are systematically missing. As an example, a pseudosymmetry prediction depending on the elements involved is discussed for binary AB compounds with B1 and B2 structure types. However, since this is impossible for more complicated phases, this approach cannot be directly applied to compounds of arbitrary composition and structure.
    Beschreibung: Distinguishing between actual and apparent pseudosymmetry in electron backscatter diffraction patterns is nearly impossible, even for simulated patterns. However, the resulting lattice is always a superlattice as long as the signal is not a superposition of multiple patterns.
    Schlagwort(e): ddc:548 ; Bravais lattices ; pseudosymmetry ; lattice point density ; ordered/disordered structures ; lattice distortion ; electron backscatter diffraction ; backscattered Kikuchi diffraction patterns ; lattice parameters ; Funk transform
    Sprache: Englisch
    Materialart: doc-type:article
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  • 129
    Publikationsdatum: 2023-07-20
    Beschreibung: The subduction of bathymetric highs, such as aseismic ridges, leads to far‐reaching changes in the dynamics of subduction zones with increased plate coupling and deformation in the upper plate. Subduction of the submarine Carnegie Ridge on the Nazca Plate has fundamentally impacted late Cenozoic magmatism and tectonic activity in the northern Andes. However, the timing of onset of Carnegie Ridge subduction has been a matter of debate. Time‐temperature inverse modeling of new thermochronological data from the Western Cordillera of Ecuador reveals two phases of cooling separated by isothermal conditions. The first cooling phase postdates early and middle Miocene magmatism in the Western Cordillera and is attributed to post‐magmatic thermal relaxation. The second cooling phase started after 6 Ma. Inferred to record the onset of tectonically controlled rock uplift and exhumation in the Western Cordillera, this phase is coeval with the last cooling phase recorded in the Eastern Cordillera. Based on these findings, we suggest that the onset of subduction of the Carnegie Ridge at ∼6–5 Ma increased plate coupling at the subduction interface, promoting shortening, regional rock uplift, and exhumation in the northern Andes. Overall, our results highlight the essential role of bathymetric highs in driving regional upper‐plate deformation at non‐collisional convergent plate margins.
    Beschreibung: Plain Language Summary: Topographic growth and morphology of the Andes have been influenced by subduction processes, tectonic inheritance, and climate. Here, we investigate the role of subduction of high topography on the ocean floor in driving deformation in the upper plate at the Nazca‐South America ocean‐continent plate margin. The subduction of the Carnegie Ridge, a linear, topographically high sector on the Nazca Plate, has impacted magmatism and deformation processes in the Ecuadorian Andes. However, the timing of onset of ridge subduction is debated. We employed radioisotopic dating techniques to evaluate the uplift of the Andes. These techniques record the cooling of rocks as mountain ranges are uplifted and eroded. The thermal histories of rocks from the Western Cordillera in Ecuador reveal two distinct cooling phases. The first cooling phase occurred shortly after Miocene magmatic bodies were emplaced in the Western Cordillera. The second cooling phase began at ∼6–5 Ma, coeval with the last cooling phase in the Eastern Cordillera. We attribute this cooling phase to the onset of uplift and erosion in the Western Cordillera. Based on these findings, we suggest that the onset of subduction of the Carnegie Ridge increased plate coupling and promoted shortening and rock uplift in the northern Andes.
    Beschreibung: Key Points: Thermochronological data reveal two cooling phases in the Western Cordillera of Ecuador, during the Miocene and after 6 Ma. The onset of cooling at 6 Ma was associated with shortening, rock uplift, and exhumation in the Western Cordillera. Mio‐Pliocene exhumation was related to stronger coupling of the subduction interface due to the initial subduction of the Carnegie Ridge.
    Beschreibung: Deutscher Akademischer Austauschdienst http://dx.doi.org/10.13039/501100001655
    Beschreibung: Potsdam University Graduate School
    Beschreibung: Yachay Tech University
    Beschreibung: Arizona LaserChron Center
    Beschreibung: https://zenodo.org/record/7311529#Y4YTYYLMITU
    Schlagwort(e): ddc:551.8 ; aseismic ridge subduction ; topographic growth ; zircon U‐Pb geochronology ; apatite and zircon (U‐Th)/He and apatite fission‐track thermochronology ; Carnegie ridge ; northern Andes
    Sprache: Englisch
    Materialart: doc-type:article
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  • 130
    Publikationsdatum: 2023-07-20
    Beschreibung: Knowledge of lithospheric structure is essential for understanding the impact of continental collision and oceanic subduction on surface tectonic configurations. Full‐waveform tomographic images reveal lateral heterogeneities and anisotropy of the lithosphere and asthenosphere in Asia. Estimating lithospheric thickness from seismic velocity reductions at depth exhibits large variations underneath different tectonic units. The thickest cratonic roots are present beneath the Sichuan, Ordos, and Tarim basins and central India. Radial anisotropy signatures of 11 representative tectonic provinces uncover the different nature and geodynamic processes of their respective past and present deformation. The large‐scale continental lithospheric deformation is characterized by low‐velocity anomalies from the Himalayan Orogen to the Baikal rift zone in central Asia, coupled with the post‐collision thickening of the crust. The horizontal low‐velocity layer of ∼100–300 km depth extent below the lithosphere points toward the existence of the asthenosphere beneath East and Southeast Asia, with heterogeneous anisotropy indicative of channel flows.
    Beschreibung: Plain Language Summary: The lithospheric plates, like mosaics of the Earth’s surface, are moving coherently over the weaker, convecting asthenosphere. The lithospheric structure and thickness dictated by mantle dynamics play a first‐order role in understanding the active tectonics and morphological evolution of the Asian region. Here, the latest high‐resolution full‐waveform tomographic model, SinoScope 1.0, is employed to investigate the seismic structure and dynamics of the lithosphere and asthenosphere from a seismological perspective. The lithospheric thickness of known various geological units and cratonic blocks is retrieved with large variability. The observed anisotropic signatures within the lithosphere and asthenosphere provide important constraints on the deformation state and history of different tectonic provinces. The India‐Eurasia collision primarily induced large‐scale lithospheric deformation and thickening of the crust in the west of the North‐South Gravity Lineament. The narrow low‐velocity layer below the lithosphere lies beneath East and Southeast Asia and is bounded by subduction trenches and cratonic blocks, which provides seismic evidence for the low‐viscosity asthenosphere that partially decouples plates from mantle flow beneath and allows plate tectonics to work above. The lithospheric thinning and extension, intensive magmatism, and mineralization are potentially associated with the strong interaction between the lithosphere and asthenospheric flow in the eastern Asian margin.
    Beschreibung: Key Points: Full‐waveform tomographic images reveal lateral heterogeneities and anisotropy in the lithosphere and asthenosphere beneath the Asian region. India‐Eurasia collision induced large‐scale low‐velocity anomaly and crustal thickening spanning from the Himalayas to the Baikal rift zone. Asthenosphere in East and SE Asia exhibits strong vsh, 〉 vsv, and partially decouples lithosphere, bounded by subduction trench and cratonic keels.
    Beschreibung: China Scholarship Council http://dx.doi.org/10.13039/501100004543
    Beschreibung: National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809
    Beschreibung: Korea Meteorological Administration Research and Development Program http://dx.doi.org/10.13039/501100003629
    Beschreibung: National Research Foundation of Korea http://dx.doi.org/10.13039/501100003725
    Schlagwort(e): ddc:551.1 ; Asia ; seismic structure ; lithosphere dynamics ; asthenosphere dynamics
    Sprache: Englisch
    Materialart: doc-type:article
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  • 131
    Publikationsdatum: 2023-07-20
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The dryness of the stratosphere is the result of air entering through the cold tropical tropopause layer (TTL). However, our understanding of the moisture flux partitioning into water vapor and frozen hydrometeors is incomplete. This raises concerns regarding the ability of General Circulation Models to accurately predict changes in stratospheric water vapor following perturbations in the radiative budget due to volcanic aerosol or stratospheric geoengineering. We present the first results using a global storm‐resolving model investigating the sensitivity of moisture fluxes within the TTL to an additional heating source. We address the question how the partitioning of moisture fluxes into water vapor and frozen hydrometeors changes under perturbations. The analysis reveals the resilience of the TTL, keeping the flux partitioning constant even at an average cold‐point warming exceeding 8 K. In the control and perturbed simulations, water vapor contributes around 80% of the moisture entering the stratosphere.〈/p〉
    Beschreibung: Plain Language Summary: The stratosphere is a dry region since moisture entering it from below has to pass the cold‐point, a temperature minimum between troposphere and stratosphere. The low temperatures lead to ice formation and sedimentation of moisture. Frozen moisture within clouds rising above the cold‐point tropopause can pass this temperature barrier and be injected into the stratosphere, where temperatures increase again, promoting the melting and sublimation of ice crystals. However, little is known about the sensitivity of the split of moisture entering the stratosphere into frozen and non‐frozen moisture, especially under external influences, like heating by volcanic aerosol or stratospheric geoengineering efforts. Convective parameterizations in conventional simulations can lead to biases. The emerging km‐scale simulations, which explicitly resolve the physical processes, offer the unique possibility to study moisture fluxes under external forcing while circumventing the downsides of parameterizations. Here, the sensitivity of the moisture flux partitioning into non‐frozen and frozen components to an additional heating source is studied for the first time in global storm‐resolving simulations. The analysis reveals an unaltered flux partitioning even at an average cold‐point warming exceeding 8 K. In the control and perturbed simulations, water vapor contributes around 80% of the moisture entering the stratosphere.〈/p〉
    Beschreibung: Key Points:Water vapor dominates the stratospheric moisture budget with a contribution of around 80% in global storm‐resolving simulation. The partitioning of stratospheric moisture fluxes into vapor and frozen hydrometeors remains stable under large temperature perturbations.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: Fueglistaler Group
    Schlagwort(e): ddc:551.5 ; stratospheric water vapor ; tropopause ; perturbation ; moisture budget ; geoengineering ; volcano
    Sprache: Englisch
    Materialart: doc-type:article
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  • 132
    Publikationsdatum: 2023-07-27
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Results from the Cassini‐Huygens space mission at Enceladus revealed a substantial inventory of organic species embedded in plume and E ring ice grains originating from a global subsurface and putative habitable ocean. Compositional analysis by the Cosmic Dust Analyzer indicated the presence of aromatic species and constrained some structural features, although their exact nature remains unclear. As indicated by many studies, among other organic species, low‐mass aromatics likely played a role in the emergence of life on Earth and may be linked to potential prebiotic or biogenic chemistry on icy moons. Here, we study the behavior of single‐ringed aromatic compounds—benzoic acid and two isomeric derivatives, 2,3‐dihydroxybenzoic acid and 2,5‐dihydroxybenzoic acid—using Laser‐Induced Liquid Beam Ion Desorption (LILBID), an analogue setup to simulate the impact ionization mass spectra of ice grains in space. These compounds share common structural features but also exhibit differences in functional groups and substituent positions. We investigate the fragmentation behavior and spectral appearance of each molecule over three simulated impact velocities, in both positive and negative ion modes. Parent compounds can be distinguished easily from their derivatives due to various spectral differences, including the (de)protonated molecular ion peaks appearing at different 〈italic〉m〈/italic〉/〈italic〉z〈/italic〉 values. We conclude that distinction between structural isomers in LILBID is more challenging, but some insights can be revealed by considering intermolecular bonding regimes. This work will guide future investigations into elucidating the composition of isomeric biosignatures in ice grains, relevant for future space missions to Enceladus and Europa.〈/p〉
    Beschreibung: Plain Language Summary: The Cassini‐Huygens space mission discovered a plume at Enceladus that ejects gases and frozen ice grains originating from an ocean of liquid water below its icy shell. In these ice grains, a range of interesting organic molecules were discovered by Cassini's Cosmic Dust Analyzer mass spectrometer. Organic molecules are important in the search for life beyond Earth as they form the basis of all known Earth life, and active biology elsewhere would likely have a discernible effect on the local inventory of organic species. One class of organic, with a ring structure of carbon atoms, called aromatics, were discovered in the plume. We investigate the spectral appearance of one example of aromatic compound, benzoic acid, as well as two similar compounds with additional chemical groups attached to the aromatic ring. The two similar compounds have the same mass and general structure, but slightly different arrangements of the additional groups, known as isomers. We find that it is simple to distinguish mass spectral features between benzoic acid and its related compounds, but more difficult to explain the differences between the isomers. This work will assist the analysis of mass spectrometry data from future habitability‐investigating space missions to ocean‐bearing icy moons.〈/p〉
    Beschreibung: Key Points: Cassini revealed a variety of organic compounds including clear evidence of aromatics in the plume of Enceladus. Identifying mass spectral features of isomeric organics enhances our ability to assess the astrobiological potential of Enceladus/Europa. Parent aromatic compounds can be easily distinguished from their derivatives in ice grains with impact ionization mass spectrometry.
    Beschreibung: European Research Council Consolidator
    Beschreibung: http://dx.doi.org/10.17169/refubium-37960
    Beschreibung: https://lilbid-db.planet.fu-berlin.de/
    Schlagwort(e): ddc:523 ; mass spectrometry ; LILBID and impact ionization ; aromatics and isomeric derivatives ; Enceladus and Europa ; space missions ; habitability
    Sprache: Englisch
    Materialart: doc-type:article
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  • 133
    Publikationsdatum: 2023-07-27
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The Radiation Assessment Detector (RAD) on board the Mars Science Laboratory's Curiosity rover has been monitoring the surface radiation environment on Mars for just over 10 years. It has been found by Wimmer‐Schweingruber et al. (2015, 〈ext-link ext-link-type="uri" xlink:href="https://doi.org/10.1002/2015gl066664"〉https://doi.org/10.1002/2015gl066664〈/ext-link〉) that within the narrow view cone of RAD, the directionality of the radiation field is close to but not completely isotropic. In order to better understand the directionality of the surface radiation over a wide range of zenith angles (〈italic〉θ〈/italic〉), we perform a three‐dimensional Geant4 Monte Carlo simulation to derive the 〈italic〉θ〈/italic〉‐dependence of the surface dose rate. The results show that galactic cosmic ray protons, coming in at 〈italic〉θ〈/italic〉 ∼ 74° make the greatest contribution to the surface dose. For helium ions, this angle is at around 46°. This is a consequence of the increasing column depth at larger zenith angles and the complex interplay of the destruction of primary and the creation of secondary particles as the primary cosmic ray interacts with the Martian atmosphere. We also compared the simulated results with the RAD measurements and found a reasonable agreement. Our results are important for future human exploration of Mars, for instance, to estimate the effectiveness of radiation shielding of a given geometry or for optimizing the radiation shielding design of a Martian habitat.〈/p〉
    Beschreibung: Plain Language Summary: Space agencies and private companies are working to place humans on the surface of Mars. Astronauts would be exposed to a different and considerably harsher radiation environment on Mars than humans are on Earth. Space radiation is largely determined by galactic cosmic rays, which have sufficient energy to reach the Martian surface. Thus, a better understanding of the radiation on the surface of Mars is needed. The shielding provided by the atmosphere increases with the zenith angle, and it also causes an increase in the creation of secondary particles. To better understand this, we perform a Geant4 Monte Carlo simulation to derive the dependence of the surface dose rate on the zenith angle 〈italic〉θ〈/italic〉. The results show that the radiation dose on the surface of Mars depends on the incoming angle of the primary radiation. Moreover, the radiation dose rate is significantly modulated by solar activity, and the Mars surface dose rate differs by about 50% between solar maximum and minimum periods. We validate our simulation by comparing the dose measured by the Mars Science Laboratory Radiation Assessment Detector and find good agreement.〈/p〉
    Beschreibung: Key Points: We model the downward radiation dose on the surface of Mars and find that it only depends weakly on the zenith angle. The surface dose rate depends on solar modulation, and weaker modulation results in higher dose rate for each.The local topographical features influence the Martian surface radiation.
    Beschreibung: Deutsches Zentrum für Luft‐und Raumfahrt http://dx.doi.org/10.13039/501100002946
    Beschreibung: Jet Propulsion Laboratory http://dx.doi.org/10.13039/100006196
    Beschreibung: Strategic Priority Program of CAS
    Beschreibung: National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809
    Beschreibung: Civil Aerospace Technologies
    Beschreibung: NASA Johnson Space Center
    Beschreibung: https://doi.org/10.17189/1519761
    Beschreibung: https://doi.org/10.17189/1519760
    Beschreibung: https://doi.org/10.17189/1523028
    Beschreibung: https://doi.org/10.5281/zenodo.7257306
    Schlagwort(e): ddc:523 ; space radiation ; Mars exploration ; MSL mission ; zenith angle
    Sprache: Englisch
    Materialart: doc-type:article
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  • 134
    Publikationsdatum: 2023-07-27
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The composition of basaltic melts in equilibrium with the mantle can be determined for several Martian meteorites and in‐situ rover analyses. We use the melting model MAGMARS to reproduce these primary melts and estimate the bulk composition and temperature of the mantle regions from which they originated. We find that most mantle sources are depleted in CaO and Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 relative to models of the bulk silicate Mars and likely represent melting residues or magma ocean cumulates. The concentrations of Na〈sub〉2〈/sub〉O, K〈sub〉2〈/sub〉O, P〈sub〉2〈/sub〉O〈sub〉5〈/sub〉, and TiO〈sub〉2〈/sub〉 are variable and often less depleted, pointing to the re‐fertilization of the sources by fluids and low‐degree melts, or the incorporation of residual trapped melts during the crystallization of the magma ocean. The mantle potential temperatures of the sources are 1400–1500°C, regardless of the time at which they melted and within the range of the most recent predictions from thermochemical evolution models.〈/p〉
    Beschreibung: Plain Language Summary: Martian meteorites and rocks analyzed by rovers are witnesses of magmatic processes on Mars. Some of the basaltic specimens among them have been classified as “primitive” as they are closely related to the melts that form in the mantle and feature high MgO/FeO. They record important properties of the mantle of Mars. We use the mantle melting model MAGMARS to constrain the temperature and composition of the mantle source regions from which primitive basalts originated. We find that the mantle compositions were low in CaO and Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, either because they melted on several occasions, or because these components were locked in deeper layers of the mantle when it solidified from the bottom up (early magma ocean). Several mantle sources are comparatively rich in Na〈sub〉2〈/sub〉O, K〈sub〉2〈/sub〉O, P〈sub〉2〈/sub〉O〈sub〉5〈/sub〉, and TiO〈sub〉2〈/sub〉. These components were either subsequently added to the mantle sources by fluids and low‐degree melts or can be explained by the trapping of melts during the progressive crystallization of the magma ocean. The temperature of the mantle sources projected to surface conditions for easier comparison (potential temperature) was 1400–1500°C, regardless of the time at which they melted, and is within the range of recent predictions from planetary‐scale models of interior dynamics.〈/p〉
    Beschreibung: Key Points: Basalts that sampled discrete mantle regions throughout Mars's history provide information about the mantle composition and temperature. The mantle potential temperature of primitive basalts appears constant (1400–1500ºC), yet is likely not representative of the average mantle. Incompatible element concentrations in the mantle vary due to magma ocean crystallization, partial melting, and metasomatism.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Deutsches Zentrum für Luft‐ und Raumfahrt http://dx.doi.org/10.13039/501100002946
    Beschreibung: https://doi.org/10.5281/zenodo.7949084
    Schlagwort(e): ddc:552 ; Martian magmatism ; mantle melting ; Mars interior structure ; depleted mantle ; metasomatism ; secular cooling
    Sprache: Englisch
    Materialart: doc-type:article
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  • 135
    Publikationsdatum: 2023-07-27
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Rockwall erosion by rockfall is largely controlled by frost weathering in high alpine environments. As alpine rock types are characterized by crack‐dominated porosity and high rock strength, frost cracking observations from low strength and grain supported pore‐space rocks cannot be transferred. Here, we conducted laboratory experiments on Wetterstein limestone samples with different initial crack density and saturation to test their influence on frost cracking efficacy. We exposed rocks to real‐rockwall freezing conditions and monitored acoustic emissions as a proxy for cracking. To differentiate triggers of observed cracking, we modeled ice pressure and thermal stresses. Our results show initial full saturation is not a singular prerequisite for frost cracking. We also observe higher cracking rates in less‐fractured rock. Finally, we find that the temperature threshold for frost cracking in alpine rocks falls below −7°C. Thus, colder, north‐exposed rock faces in the Alps likely experience more frost cracking than southern‐facing counterparts.〈/p〉
    Beschreibung: Plain Language Summary: Freezing results in the formation of ice that exerts stresses on fracture walls and draws in additional moisture to supply further growth and break down rocks, a process termed frost cracking. Frost cracking drives much erosion and rockfall in alpine environments. Here we test hypotheses from prior work about how frost cracking is impacted by saturation and rock properties. We exposed rock samples of different strength and saturation to identical freezing conditions in laboratory experiments. We monitored rock temperature and acoustic emissions (AE), assuming frost cracking produces the recorded AE hits. We find that initial full saturation is not required for frost cracking, as water transport is enhanced by fractures in alpine rocks. Furthermore, rock with initial higher short‐term strength showed more frost cracking because, we infer, of stiffness properties that make these rocks more brittle compared to lower strength rocks. Frost cracking occurred at a wide range of temperatures below freezing and was highest between −9 and −7°C. We thus conclude that frost cracking is most impacted by temperature and rock short‐term strength. In Alpine environments, this may result in more frost cracking and rockfall on colder north‐facing rockwalls than warmer southern exposures.〈/p〉
    Beschreibung: Key Points: Initial saturation levels do not limit the efficacy of ice segregation in fractured alpine rocks. Rock initial crack density impacts rock stiffness and thermal properties and thus frost cracking efficacy. The “frost cracking window” temperature range is dependent on rock strength and crack‐controlled porosity in alpine rocks.
    Beschreibung: German Reserach Foundation
    Beschreibung: https://doi.org/10.6084/m9.figshare.23584686
    Schlagwort(e): ddc:551.3 ; frost weathering ; frost cracking ; periglacial processes ; rock weathering ; thermal stress ; acoustic emission
    Sprache: Englisch
    Materialart: doc-type:article
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  • 136
    Publikationsdatum: 2023-07-27
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉In this paper we describe a method to compute spatial scales for images acquired by NASA's Mars Curiosity rover (Mars Science Laboratory, MSL). The method is based on the assumption that the rover stands on an infinite plane that may have any orientation with respect to the local gravity vector. While not new, it is the first time that this method is systematically applied to Martian images acquired by a lander. A continuously run software pipeline processes the images acquired by the rover within a 20 m radius, adds approximate scalebars to the raw images, and generates, whenever possible, rectified (warped) versions of those images. The products of this software pipeline and the chemical compositions of relevant rover science targets from NASA's Planetary Data System archive, are made available to the public via the Approximate Scale for Images and Chemistry website, which has been developed in collaboration with the Planetary Data System Analyst's Notebook for the MSL mission. Hyperlinks connect the two resources.〈/p〉
    Beschreibung: Plain Language Summary: We developed a software pipeline that calculates the spatial scale of images acquired by NASA's Mars Curiosity rover. The software pipeline is linked to a new website: the Approximate Scale for Images and Chemistry, in which the scalebar products are paired with information about the shape, size, color, and chemical composition of the imaged site, obtained by the rover suite of instruments. The images mimic the vantage point of human eyes and are therefore well‐suited to inspire field geologists (including those mainly working on Earth) to interpret Martian geologic features.〈/p〉
    Beschreibung: Key Points: A systematic method to generate approximate scalebars for obliquely acquired Martian landscape images was developed. A newly created Approximate Scale for Images and Chemistry (ASIC) website links images, color, spatial scale, and chemistry, as returned by NASA's Curiosity rover in Gale crater. The ASIC website is complementary and strongly linked to the Analyst's Notebook, the data resource for Martian/lunar landed missions.
    Beschreibung: Deutsche Forschungsgemeinschaft
    Beschreibung: Project DEAL
    Beschreibung: https://asic.mps.mpg.de/
    Beschreibung: https://an.rsl.wustl.edu/msl/
    Beschreibung: http://pds-geosciences.wustl.edu/msl/msl-m-chemcam-libs-4_5-rdr-v1/mslccm_1xxx/data/moc/
    Beschreibung: http://pds-geosciences.wustl.edu/msl/msl-m-chemcam-libs-4_5-rdr-v1/mslccm_1xxx/extras/rmi_mosaics/
    Beschreibung: http://pds-geosciences.wustl.edu/msl/msl-m-chemcam-libs-4_5-rdr-v1/mslccm_1xxx/extras/rmi_contours_in_mcam_images/
    Beschreibung: http://pds-geosciences.wustl.edu/msl/msl-m-apxs-4_5-rdr-v1/mslapx_1xxx/extras/
    Schlagwort(e): ddc:523 ; Mars ; Curiosity rover ; images ; spatial scale ; science targets ; chemistry
    Sprache: Englisch
    Materialart: doc-type:article
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  • 137
    Publikationsdatum: 2023-07-28
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The Lagrangian representation of fluid flows offers a natural perspective to study many kinds of physical mechanisms. By contrast, the Eulerian representation is more convenient from a diagnostic point of view. This article attempts to combine elements of both worlds by proposing an Eulerian method that allows one to extract Lagrangian information about the atmospheric flow. The method is based on the offline advection of passive tracer fields and includes a relaxation term. The latter device allows one to run the integration in a continuous fashion without the need for reinitialization. As a result one obtains accumulated Lagrangian information, for example, about the recent parcel displacement or the recent parcel‐based diabatic heating, at each point of an Eulerian grid at any time step. The method is implemented with a pseudospectral algorithm suitable for gridded global atmospheric data and compared with the more traditional trajectory method. The method's utility is demonstrated on the basis of a few examples, which relate to cloud formation and the development of temperature anomalies. The examples highlight that the method provides a convenient diagnostic of parcel‐based changes, paving an intuitive way to explore the physical processes involved. Due to its gridpoint‐based nature, the proposed method can be applied to large data sets in a straightforward and computationally efficient manner, suggesting that the method is particularly useful for climatological analyses.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The Lagrangian representation of fluid flows offers the most natural perspective to study many kinds of physical mechanisms; by contrast, the Eulerian representation is more convenient from a diagnostic point of view. This article attempts to combine elements of both worlds by proposing an Eulerian method that allows one to extract Lagrangian information about the atmospheric flow. The method enables one to easily produce a sequence of maps showing accumulated Lagrangian changes. 〈boxed-text position="anchor" id="qj4453-blkfxd-0001" content-type="graphic" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:00359009:media:qj4453:qj4453-toc-0001"〉 〈/boxed-text〉〈/p〉
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Schlagwort(e): ddc:551.5 ; air‐parcel approach ; atmospheric fluid dynamics ; atmospheric transport ; Eulerian tracer technique ; Lagrangian analysis ; Lagrangian tracking ; synoptic‐scale meteorology ; trajectories
    Sprache: Englisch
    Materialart: doc-type:article
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  • 138
    Publikationsdatum: 2023-07-04
    Beschreibung: The recent diversification of macromolecular crystallographic experiments including the use of pink beams, convergent electron diffraction and serial snapshot crystallography has shown the limitations of using the Laue equations for diffraction prediction. This article gives a computationally efficient way of calculating approximate crystal diffraction patterns given varying distributions of the incoming beam, crystal shapes and other potentially hidden parameters. This approach models each pixel of a diffraction pattern and improves data processing of integrated peak intensities by enabling the correction of partially recorded reflections. The fundamental idea is to express the distributions as weighted sums of Gaussian functions. The approach is demonstrated on serial femtosecond crystallography data sets, showing a significant decrease in the required number of patterns to refine a structure to a given error.
    Beschreibung: Reflection position, size and shape prediction and partiality estimation of crystal diffraction by integrating using a Gaussian basis are described.
    Schlagwort(e): ddc:548 ; partiality estimation ; diffraction prediction ; merging ; serial snapshot crystallography
    Sprache: Englisch
    Materialart: doc-type:article
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  • 139
    facet.materialart.
    Unbekannt
    ARGE GMIT, Bonn
    Publikationsdatum: 2023-07-04
    Beschreibung: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom Juni 2022 enthält die Themenblöcke: GEOfokus:Mariengraben - Am Puls der tiefen Erde, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Beschreibung: DFG, SUB Göttingen
    Beschreibung: journal
    Schlagwort(e): ddc:550 ; GMIT
    Sprache: Deutsch
    Materialart: doc-type:book , publishedVersion
    Format: 124
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  • 140
    Publikationsdatum: 2023-07-04
    Beschreibung: The Andean Plateau of north‐western Argentina (Puna) at a mean elevation of ca. 4.2 km constitutes the southern continuation of the Altiplano; it is a compressional basin‐and‐range province comprising fault‐bounded, high‐elevation mountain ranges and largely internally drained basins with often thick sedimentary and volcaniclastic fill. Growing sedimentological and structural evidence supports the notion that the north‐western Argentine Andes between 22° and 26°S developed from an initial extensive broken‐foreland system that extended across the present‐day eastern Andean flank during the early to middle Eocene. However, compelling evidence of the tectonic history of this region is still missing. Here, we present new apatite fission track and zircon (U–Th)/He thermochronological data and U–Pb zircon ages from intercalated volcanic ash deposits from the Pastos Chicos Basin (23.5°S, 66.5°W) to constrain basin formation and the timing of major crustal deformation in the northern Puna. Inverse thermal modeling of the thermochronological data provides further temporal constraints on the late Cenozoic cooling history of the crust in this region and, by inference, on the timing of upper‐crustal shortening, range uplift, and basin formation in the northern sector of the present‐day Puna Plateau. Specifically, we argue for plateau‐wide distributed deformation in the Eocene between 23° and 24°S, followed by spatially disparate and diachronous deformation (Oligocene to Pliocene).
    Beschreibung: Plain Language Summary: The Argentine Puna Plateau is a mountainous region in the Central Andes of South America. It is the result of the tectonic convergence between the oceanic Nazca Plate and the continental South American Plate. However, the detailed tectonic evolution of this region is yet unknown. We present new thermochronologic data from the Puna Plateau that allow inferences about crustal deformation and mountain range uplift. Combined with previous studies, our results suggest deformation distributed over the entire plateau during the Eocene. Thereafter, local deformation occurred spatially non‐systematic, possibly related to zones of weakness in the crust.
    Beschreibung: Key Points: Thermal modeling of apatite fission track and (U‐Th)/He zircon data from the Pastos Chicos Basin shows Oligo‐Miocene onset of exhumation. Regional compilation of spatio‐temporal deformation at 23°–24°S suggests out‐of‐sequence deformation related to basement heterogeneities. Mio‐Pliocene U–Pb zircon ages of volcanic ash deposits refine the chronostratigraphy of the Pastos Chicos Basin.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Brandenburg Ministry of Sciences, Research and Cultural Affairs, Germany
    Beschreibung: Blaustein Fund
    Beschreibung: Fulbright Foundation
    Beschreibung: France‐Stanford Center for Interdisciplinary Studies
    Beschreibung: https://doi.org/10.6084/m9.figshare.20209865.v1
    Schlagwort(e): ddc:551.8 ; Puna Plateau ; NW Argentina ; thermochronology ; U–Pb zircon geochronology ; mountain range uplift ; Tectonics
    Sprache: Englisch
    Materialart: doc-type:article
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  • 141
    Publikationsdatum: 2023-07-21
    Beschreibung: Oceanic circulation and mass‐field variability play important roles in exciting Earth's wobbles and length‐of‐day changes (ΔΛ), on time scales from days to several years. Modern descriptions of these effects employ oceanic angular momentum (OAM) series from numerical forward models or ocean state estimates, but nothing is known about how ocean reanalyses with sequential data assimilation (DA) would fare in that context. Here, we compute daily OAM series from three 1/4° global ocean reanalyses that are based on the same hydrodynamic core and input data (e.g., altimetry, Argo) but different DA schemes. Comparisons are carried out (a) among the reanalyses, (b) with an established ocean state estimate, and (c) with Earth rotation data, all focusing on the period 2006–2015. The reanalyses generally provide credible OAM estimates across a range of frequencies, although differences in amplitude spectra indicate a sensitivity to the adopted DA scheme. For periods less than 120 days, the reanalysis‐based OAM series explain ∼40%–50% and ∼30%–40% of the atmosphere‐corrected equatorial and axial geodetic excitation, similar to what is achieved with the state estimate. We find mixed performance of the reanalyses in seasonal excitation budgets, with some questionable mean ocean mass changes affecting the annual cycle in ΔΛ. Modeled excitations at interannual frequencies are more uncertain compared to OAM series from the state estimate and show hints of DA artifacts in one case. If users are to choose any of the tested reanalyses for rotation research, our study points to the Ocean Reanalysis System 5 as the most sensible choice.
    Beschreibung: Key Points: We evaluate three ocean reanalyses for their skill in explaining Earth rotation variations on different time scales from 2006 to 2015. For periods 〈120 days, reanalyses explain 40%–50% of atmosphere‐reduced polar motion excitation variance, similar to an ocean state estimate. Reanalyses show mixed skill in seasonal excitation budgets and, in one case, hints of data assimilation artifacts at interannual periods.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: https://resources.marine.copernicus.eu/product-detail/GLOBAL_REANALYSIS_PHY_001_031/INFORMATION
    Beschreibung: https://isdc.gfz-potsdam.de/ggfc-oceans/oam/
    Beschreibung: https://www.ncei.noaa.gov/access/metadata/landing-page/bin/iso?id=gov.noaa.ngdc.mgg.dem:316
    Beschreibung: https://podaac-tools.jpl.nasa.gov/drive/files/GeodeticsGravity/tellus/L3/mascon/RL06/JPL/v02/CRI/netcdf
    Beschreibung: https://keof.jpl.nasa.gov/combinations/
    Schlagwort(e): ddc:550 ; Earth rotation ; ocean angular momentum ; ocean reanalysis ; data assimilation
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 142
    Publikationsdatum: 2023-07-21
    Beschreibung: A band width determination using the first derivative of the band profile systematically underestimates the true Bragg angle. Corrections are proposed to compensate for the resulting offset Δa/a of the mean lattice parameters derived from as many Kikuchi band widths as possible. For dynamically simulated Kikuchi patterns, Δa/a can reach up to 8% for phases with a high mean atomic number Z, whereas for much more common low‐Z materials the offset decreases linearly. A predicted offset Δa/a = f(Z) is therefore proposed, which also includes the unit‐cell volume and thus takes into account the packing density of the scatterers in the material. Since Z is not always available for unknown phases, its substitution by Zmax, i.e. the atomic number of the heaviest element in the compound, is still acceptable for an approximate correction. For simulated Kikuchi patterns the offset‐corrected lattice parameter deviation is Δa/a 〈 1.5%. The lattice parameter ratios, and the angles α, β and γ between the basis vectors, are not affected at all.
    Beschreibung: Automatically determined band widths in simulated backscatter Kikuchi patterns exhibit differences from the double Bragg angles that correlate with the scatterer density. Corrections are proposed to compensate for this.
    Schlagwort(e): ddc:548 ; mean atomic number ; Kikuchi patterns ; lattice parameters ; automated Bragg angle determination ; lattice parameter determination ; dynamical theory of electron diffraction ; electron backscatter diffraction ; Funk transform
    Sprache: Englisch
    Materialart: doc-type:article
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  • 143
    Publikationsdatum: 2023-07-21
    Beschreibung: The presence of the Etendeka flood basalts in northwestern Namibia is taken as evidence for the activity of the Tristan da Cunha mantle plume during the continental breakup between Africa and South America. We investigate seismic anisotropy beneath NW Namibia by splitting analysis of core‐refracted teleseismic shear waves (XKS phases) to probe mantle flow and lithospheric deformation related to the tectonic history of the region. We present the results of the joint splitting analysis of XKS data collected from 34 onshore stations and 12 ocean‐bottom seismometers. The fast polarization directions (FPDs) are consistent with a model that combines the effects of lithospheric deformation and large‐scale mantle flow due to the NE motion of the African plate. The dominantly NNW‐SSE‐oriented FPDs in the northern part are likely caused by shallow lithospheric structures. Our observations do not show any strong evidence of a pervasive effect of the Tristan da Cunha mantle plume.
    Beschreibung: Plain Language Summary: The geology of Northwest Namibia is characterized by the presence of flood basalts, originating from magma sourced in the Earth's mantle. The source magma of these flood basalts was produced during the passage of the African plate over a mantle plume, more than 80 million years ago, contemporaneous with the onset of the breakup of the South American plate from the African plate. The role of the mantle plume in the continental breakup can be examined by a seismological technique named shear wave splitting analysis. The mantle flow induces direction‐dependent physical properties, that is, seismic anisotropy, which causes a shear wave to split into two different components traveling at different speeds. The leading component is polarized in a direction representing the direction of the flow in the earth's mantle. Except for the northern part, the polarization direction of the fast shear wave is consistent with the model of mantle flow caused by the NE motion of the African plate and deformations in the lithosphere. The results of our study do not show any direct evidence for the direct impact of the mantle plume on the mantle beneath our region of study.
    Beschreibung: Key Points: Upper mantle anisotropy beneath NW Namibia is a combined effect of the present‐day motion of the African Plate and lithospheric structures. No significant direct effect of the Tristan da Cunha mantle plume is observed in shear wave splitting measurements. Localized shearing in the lithosphere and crustal underplating are likely the main causes of the lateral variations in seismic anisotropy.
    Beschreibung: https://doi.org/10.14470/KP6443475642
    Beschreibung: https://doi.org/10.14470/1N134371
    Beschreibung: https://doi.org/10.7914/SN/IU
    Beschreibung: https://doi.org/10.18715/SKS_SPLITTING_DATABASE
    Beschreibung: https://www.geophysik.uni-frankfurt.de/64002762/Software
    Schlagwort(e): ddc:551.1 ; seismic anisotropy ; Tristan da Cunha mantle plume ; Namibia ; lithospheric shearing ; continental breakup ; shear wave splitting
    Sprache: Englisch
    Materialart: doc-type:article
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  • 144
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Heat flow across oceanic transform faults (TFs) and fracture zones (FZs) has rarely been studied in detail, despite these features representing distinct thermal boundaries within the oceanic lithosphere. Here, we present heat flow measurements across the St Paul fracture zone (SPFZ) in the equatorial Atlantic Ocean, from 48 Ma crust in the south to 71 Ma in the north. To the north of the FZ we find a basal heat flow of 63 mWm〈sup〉−2〈/sup〉, and to the south a basal heat flow of 79 mWm〈sup〉−2〈/sup〉, both in agreement with plate cooling models. However, within the SPFZ we find a heat flow of 83 mWm〈sup〉−2〈/sup〉, greater than the values of the adjacent crust and 10–15 mWm〈sup〉−2〈/sup〉 higher than predicted from conductive cooling models, suggesting that the thermal structure of the FZ has been modified. Evidence from seismic and sub‐bottom profiler data indicate recent active deformation within the SPFZ, potentially driven by lithospheric flexure across the FZ or temporal changes in TF configuration. We propose that this deformation may enable fluid circulation and heat advection within the basement, creating the seafloor heat flow anomaly within the FZ. These findings suggest that FZs may remain important zones predisposed to host deformation and fluid flow in the oceanic lithosphere, despite not being active plate boundaries.〈/p〉
    Beschreibung: Key Points: A high heat flow anomaly of 10–15 mWm〈sup〉−2〈/sup〉 is observed in the St Paul fracture zone compared to the adjacent oceanic crust. The heat flow anomaly is likely due to tectonically driven fluid flow but thermal rejuvenation at the transform fault could also contribute. Fracture zones may act as high permeability pathways for fluid flow, and form and evolve differently to standard oceanic lithosphere.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: FP7 Ideas: European Research Council http://dx.doi.org/10.13039/100011199
    Beschreibung: https://doi.pangaea.de/10.1594/PANGAEA.950419
    Beschreibung: https://doi.pangaea.de/10.1594/PANGAEA.950420
    Schlagwort(e): ddc:551 ; fracture zone ; heat flow ; oceanic crust ; St Paul ; fluid flow ; lithosphere
    Sprache: Englisch
    Materialart: doc-type:article
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  • 145
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Parameterised by the Love number 〈italic〉k〈/italic〉〈sub〉2〈/sub〉 and the tidal quality factor 〈italic〉Q〈/italic〉, and inferred from lunar laser ranging (LLR), tidal dissipation in the Moon follows an unexpected frequency dependence often interpreted as evidence for a highly dissipative, melt‐bearing layer encompassing the core‐mantle boundary. Within this, more or less standard interpretation, the basal layer's viscosity is required to be of order 10〈sup〉15〈/sup〉–10〈sup〉16〈/sup〉 Pa s and its outer radius is predicted to extend to the zone of deep moonquakes. While the reconciliation of those predictions with the mechanical properties of rocks might be challenging, alternative lunar interior models without the basal layer are said to be unable to fit the frequency dependence of tidal 〈italic〉Q〈/italic〉. The purpose of our paper is to illustrate under what conditions the frequency‐dependence of lunar tidal 〈italic〉Q〈/italic〉 can be interpreted without the need for deep‐seated partial melt. Devising a simplified lunar model, in which the mantle is described by the Sundberg‐Cooper rheology, we predict the relaxation strength and characteristic timescale of elastically accommodated grain boundary sliding in the mantle that would give rise to the desired frequency dependence. Along with developing this alternative model, we test the traditional model with a basal partial melt; and we show that the two models cannot be distinguished from each other by the available selenodetic measurements. Additional insight into the nature of lunar tidal dissipation can be gained either by measurements of higher‐degree Love numbers and quality factors or by farside lunar seismology.〈/p〉
    Beschreibung: Plain Language Summary: As the Moon raises ocean tides on the Earth, the Earth itself gives rise to periodic deformation of the Moon. Precise measurements of lunar shape and motion can reveal those deformations and even relate them to our natural satellite's interior structure. In this work, we discuss two interpretations of those measurements. According to the first one, the lunar interior is hot and a small part of it might have melted, forming a thick layer of weak material buried more than 1,000 km deep under the lunar surface. According to the second one, there is no such layer, and the measured deformation can be explained by the behavior of solid rocks at relatively low temperatures. We show that the two possibilities cannot be distinguished from each other by the existing data.〈/p〉
    Beschreibung: Key Points: A lunar mantle governed by the Andrade model fits selenodetic constraints only with a very weak frequency dependence of tidal dissipation. We seek the parameters of two more complex models that may explain the anomalous frequency dependence of tidal 〈italic〉Q〈/italic〉 measured by lunar laser ranging. Both a dissipative basal layer and elastically accommodated grain‐boundary sliding in the deep mantle can result in the same tidal response.
    Beschreibung: Czech Science Foundation
    Beschreibung: https://doi.org/10.5281/zenodo.7788121
    Schlagwort(e): ddc:523 ; Moon ; tidal dissipation ; interior structure
    Sprache: Englisch
    Materialart: doc-type:article
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  • 146
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Hydroxyl defects in nominally anhydrous minerals (NAMs) were potential carriers of water in the early Solar System and might have contributed to the accretion of terrestrial water. To better understand this, we have conducted a nanoscale secondary ion mass spectrometry survey of water contents in olivine and orthopyroxene from a set of equilibrated ordinary chondrites of the L and LL groups (Baszkówka, Bensour, Kheneg Ljouâd, and Tuxtuac) and several ultramafic achondrites (Zakłodzie, Dhofar 125, Northwest Africa [NWA] 4969, NWA 6693, and NWA 7317). For calibration, we used terrestrial olivine and orthopyroxene with H〈sub〉2〈/sub〉O contents determined by Fourier transform infrared. Our 99.7% (~3SD) detection limits are 3.6–5.4 ppmw H〈sub〉2〈/sub〉O for olivine and 7.7–10.9 ppmw H〈sub〉2〈/sub〉O for orthopyroxene. None of the meteoritic samples studied consistently shows water contents above the detection limits. A few exceptions slightly above the detection limits are suspected of terrestrial contamination by ferric oxyhydroxides. If the meteorite samples investigated accreted in the presence of small amounts of water ice, the upper limits of water contents provided by our survey suggest that the retention of hydrogen during thermal metamorphism and differentiation was ineffective. We suggest that loss occurred through combinations of low internal pressures, high permeability along grain boundaries, and speciation of hydrogen into reduced compounds such as H〈sub〉2〈/sub〉 and methane, which are less soluble in NAMs than in water.〈/p〉
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Europlanet 2020 RI
    Schlagwort(e): ddc:549 ; chondrites ; achondrites ; olivine ; orthopyroxene ; water contents
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 147
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Due to the complexity of 2D magnetic anomaly maps north of 18°S and the sparsity of seismic data, the tectonic evolution of the northern Lau Basin has not yet been unraveled. We use a multi‐method approach to reconstruct the formation of the basin at ∼16°S by compiling seismic, magnetic, gravimetric and geochemical data along a 185 km‐long crustal transect. We identified a crustal zonation which preserves the level of subduction input at the time of the crust's formation. Paired with the seafloor magnetization, the crustal zonation enabled us to qualitatively approximate the dynamic spreading history of the region. Further assessment of the recent tectonic activity and the degree of tectonic overprinting visible in the crust both suggest a complex tectonic history including a dynamically moving spreading center and the reorganizing of the local magma supply. Comparing the compiled data sets has revealed substantial differences in the opening mechanisms of the two arms of the Overlapping Spreading Center (OSC) that is made up by the northernmost tip of the Fonualei Rift and Spreading Center in the east and the southernmost segment of the Mangatolu Triple Junction in the west. The observed transition from a predominantly tectonic opening mechanism at the eastern OSC arm to a magmatic opening mechanism at the western OSC arm coincides with an equally sharp transition from and strongly subduction influenced crust to a crust with virtually no subduction input. The degree of subduction input alters the geochemical composition, as well as the lithospheric stress response.〈/p〉
    Beschreibung: Plain Language Summary: The opening of back‐arc basins is often described as analogy to mid‐ocean ridge spreading, where the only difference is the force driving the extension. However, the northern Lau Basin is a prime example for the shortcomings of this analogy since its crust preserves an image of its complex tectonic history. The complexity results from the short‐lived nature of zones of active rifting and spreading in the northern Lau Basin, which is very different from the temporally and spatially steady nature of spreading centers at mid‐ocean ridges. The analysis of different methods (wide angle seismic data using ocean bottom seismometers, multi‐channel seismic, magnetic, gravity, and geochemical data) has led us to conclude that the Lau Basin's crust at 15°30–17°20′S was formed by a dynamically changing, both in regard of magma composition and position, extensional system that consists of the Fonualei Rift and Spreading Center and the Mangatolu Triple Junction. Nevertheless, the crustal zonation, formed by the varying subduction influence during its formation, is still preserved and affects the stress response of the crust and thus the present‐day tectonic behavior.〈/p〉
    Beschreibung: Key Points: Oceanic crust in the north‐eastern Lau Basin formed at the now reorganized FRSC‐MTJ system. The position and the opening mechanisms of back‐arc basin spreading center's change more dynamically than at mid‐ocean ridges. Different opening mechanisms at the southern Mangatolu Triple Junction and northern Fonualei Rift Spreading Center despite their proximity.
    Beschreibung: German Ministry of Science and Education
    Beschreibung: GEOMAR Helmholtz Centre for Ocean Research Kiel
    Beschreibung: Federal Institute for Geosciences and Natural Resources
    Beschreibung: https://doi.org/10.1594/PANGAEA.945716
    Beschreibung: https://doi.org/10.1594/PANGAEA.945716
    Schlagwort(e): ddc:551.1 ; Lau Basin ; back‐arc basins ; multi‐disciplinary approach ; crustal evolution ; traveltime tomography ; extension dynamics
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 148
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The Red Sea is an ideal location for studying rifting processes, offering a young and active intra‐continental rift at the final stages of breakup. We explore the 3D lithospheric structure of the Red Sea by analyzing the gravity response of four end‐member models of rift architecture, including two end‐member types margin architecture Type I—narrow margins and exhumed lithospheric mantle, and Type II—(ultra)wide margins and removal of lithospheric mantle. Additionally, we test two options for the distribution of the oceanic crust (a) limited, that is, confined only to regions of magnetic stripes, and (b) extended, that is, available in vast areas within the basin. South of latitude 23°N, our results suggest the presence of ultrawide margins and limited oceanic crust. North of this latitude, the model of exhumed mantle and limited oceanic crust has minimized residuals compared to the observed gravity field, and agrees with a previously published regional tomographic model. Additionally, we find evidence for the presence of a high‐density body along the southern Arabian coast, probably associated with magmatic underplating. We discuss the lithospheric structure of the Red Sea with respect to the nearby Afar plume, agreeing that the close proximity of the central‐southern regions to the plume promoted a reduction in the strength of the lithosphere, and led to the development of ultrawide margins in these areas.〈/p〉
    Beschreibung: Plain Language Summary: The Red Sea is a young example of continental break‐up, a process in which a continent disintegrate into smaller pieces and an ocean is formed between them. We explore the sub‐surface structure of the Red Sea, down to 140 km, aiming to better understand the mechanisms that allowed the Arabian plate to separate from Africa ∼23 million years ago. We examine the gravity response of four end‐member models of rift structures and compare them to the gravity signal measured in this region. We find that the sub‐surface structure in the central‐southern region is different than in the northern regions. Toward the south, the crust is thin and stretched, the lithospheric mantle is absent, and the asthenosphere is rising in a wide region. In the north the lithospheric mantle is exhumed and the asthenosphere is rising in narrow regions below the center of the basin. We discuss the reasons for these differences and support the possibility that the Afar Plume, currently located to the south of the Red Sea, had a thermal weakening effect on the central‐southern regions of the Red Sea, which allowed the lithosphere to deform more easily, having direct implications in the present‐day architecture of the Red Sea.〈/p〉
    Beschreibung: Key Points: Gravity modeling in the Red Sea suggests a contrasting rift architecture in the central‐southern regions and in the northern regions. In the central‐southern regions, ultrawide margins and thinned continental crust are underlaid by a broad asthenosphere upwelling. In the northern regions, we infer exhumed mantle lithosphere and a narrow asthenosphere upwelling.
    Beschreibung: Minerva Foundation http://dx.doi.org/10.13039/501100001658
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: http://icgem.gfz-potsdam.de/calcgrid
    Beschreibung: https://www.gebco.net/data_and_products/gridded_bathymetry_data/#global
    Beschreibung: https://ngdc.noaa.gov/mgg/sedthick/
    Beschreibung: https://ds.iris.edu/ds/products/emc-af2019/
    Beschreibung: https://zenodo.org/record/5771863#.Y6gmBHZBzfs
    Beschreibung: https://zenodo.org/record/4482096#.Y6gnPHZBzfs
    Beschreibung: https://igmas.git-pages.gfz-potsdam.de/igmas-pages/
    Schlagwort(e): ddc:551.1 ; Red Sea ; gravity anomaly ; passive margins ; rifting ; Afro Arabian rift ; Sediment thickness
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 149
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Gravity waves (GW) carry energy and momentum from the troposphere to the middle atmosphere and have a strong influence on the circulation there. Global atmospheric models cannot fully resolve GWs, and therefore rely on highly simplified GW parametrizations that, among other limitations, account for vertical wave propagation only and neglect refraction. This is a major source of uncertainty in models, and leads to well‐known problems, such as the late break‐up of polar vortex due to the “missing” GW drag around 60°S. To investigate these phenomena, GW observations over Southern Andes were performed during SouthTRAC aircraft campaign. This paper presents measurements from a SouthTRAC flight on 21 September 2019, including 3‐D tomographic temperature data of the infrared limb imager GLORIA (8–15 km altitude) and temperature profiles of the ALIMA lidar (20–80 km altitude). GLORIA observations revealed multiple overlapping waves of different wavelengths. 3‐D wave vectors were determined from the GLORIA data and used to initialize a GW ray‐tracer. The ray‐traced GW parameters were compared with ALIMA observations, showing good agreement between the instruments and direct evidence of oblique (partly meridional) GW propagation. ALIMA data analysis confirmed that most waves at 25–40 km altitudes were indeed orographic GWs, including waves seemingly upstream of the Andes. We directly observed horizontal GW refraction, which has not been achieved before SouthTRAC. Refraction and oblique propagation caused significant meridional transport of horizontal momentum as well as horizontal momentum exchange between waves and the background flow all along the wave paths, not just in wave excitation and breaking regions.〈/p〉
    Beschreibung: Plain Language Summary: Gravity waves (GW) are temperature and wind disturbances in the atmosphere that carry energy and momentum from troposphere to the middle atmosphere and have a strong influence on the circulation there. Global atmospheric models currently cannot adequately represent GW propagation: the facts that GWs can change wavefront orientation (refraction) and travel horizontally (and not just vertically) are typically neglected. This leads to important known model inaccuracies, for example, too low temperatures in southern polar regions. SouthTRAC aircraft measurement campaign observed GWs exited by wind flow over the Southern Andes in September–November 2019. Temperature measurements were conducted with the IR spectrometer GLORIA (provided 3‐D data) and the ALIMA lidar instrument. GLORIA data revealed many overlapping waves of different wavelengths, their propagation further up was investigated using ray‐tracing. Most waves seen by GLORIA were ray‐traced to ALIMA observations where their parameters were confirmed, thus validating our ray‐tracing technique and the two instruments against each other. We directly observed wave propagation in both vertical and horizontal directions and change in horizontal wave orientation (the latter was not seen before SouthTRAC). Due to these phenomena, many GWs carried momentum that had different directions and was deposited in a different location than most models typically predict.〈/p〉
    Beschreibung: Key Points: High‐resolution multi‐instrument measurements of orographic gravity waves (GWs) over the Andes were carried out. Oblique GW propagation and strong horizontal refraction were observed and analyzed using ray‐tracing. Significant redistribution of horizontal momentum due to horizontal refraction was observed all along the path of wave propagation.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: German Ministry for Education and Research
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: https://www.ecmwf.int/en/forecasts/datasets
    Beschreibung: https://doi.org/10.5281/zenodo.7155729
    Schlagwort(e): ddc:551.5 ; gravity waves ; refraction ; remote sensing ; lidar ; ray‐tracing
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 150
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The countless kettle holes in the Late Pleistocene landscapes of Northern Europe are hotspots for biodiversity and biogeochemical processes. As a rule, they are hydraulically connected to the shallow groundwater system. The rapid, intensive turnover of carbon, nutrients and pollutants in the kettle holes therefore has a major impact on the quality of the shallow groundwater downstream. As a result of high‐evapotranspiration rates from their riparian vegetation or strong storm events, the process of downstream groundwater flow may stagnate and reverse back towards the kettle hole, making interactions between the groundwater and kettle hole more complex. Furthermore, the highly heterogeneous soil landscape in the catchment contributes to this complexity. Therefore, the present study aims to enhance our understanding of this complicated interaction. To this end, 24 model variants were integrated into HydroGeoSphere, capturing a wide range of uncertainties in quantifying the extent and timing of groundwater flow reversal between a kettle hole and the adjacent aquifer. The findings revealed that the groundwater flow reversal lasted between 1 month and 19 years at most and occurred in a distance of more than 140 m downstream of the kettle hole. Our results demonstrated that the groundwater flow reversal arises especially often in areas where the shallow aquifer possesses low‐hydraulic conductivity. There may also be a recurrent circulating flow between the groundwater and kettle hole, resulting in solute turnover within the kettle hole. This holds particularly true in dry periods with medium to low‐water levels within the kettle hole and a negative water balance. However, shallow groundwater flow reversals are not necessarily a consequence of seasonal effects. In this respect, the properties of the local shallow aquifer by far outweigh the effect of the kettle hole location in the regional flow regime.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Frequency of the direction of water flow from a kettle hole towards the aquifer and its reversal for different aquifer sediments on a vertically cross section through the water body and the surrounding aquifer.〈boxed-text position="anchor" content-type="graphic" id="hyp14890-blkfxd-0001" xml:lang="en"〉 〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:08856087:media:hyp14890:hyp14890-toc-0001"〉
    Beschreibung: https://open-research-data.zalf.de/default.aspx
    Schlagwort(e): ddc:551.49 ; groundwater flow reversal ; HydroGeoSphere ; kettle hole ; numerical experiment ; surface–groundwater interaction
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 151
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The high‐intensity time‐of‐flight (TOF) neutron diffractometer POWTEX for powder and texture analysis is currently being built prior to operation in the eastern guide hall of the research reactor FRM II at Garching close to Munich, Germany. Because of the world‐wide 〈sup〉3〈/sup〉He crisis in 2009, the authors promptly initiated the development of 〈sup〉3〈/sup〉He‐free detector alternatives that are tailor‐made for the requirements of large‐area diffractometers. Herein is reported the 2017 enterprise to operate one mounting unit of the final POWTEX detector on the neutron powder diffractometer POWGEN at the Spallation Neutron Source located at Oak Ridge National Laboratory, USA. As a result, presented here are the first angular‐ and wavelength‐dependent data from the POWTEX detector, unfortunately damaged by a 50〈italic〉g〈/italic〉 shock but still operating, as well as the efforts made both to characterize the transport damage and to successfully recalibrate the voxel positions in order to yield nonetheless reliable measurements. Also described is the current data reduction process using the 〈italic〉PowderReduceP2D〈/italic〉 algorithm implemented in 〈italic〉Mantid〈/italic〉 [Arnold 〈italic〉et al.〈/italic〉 (2014). 〈italic〉Nucl. Instrum. Methods Phys. Res. A〈/italic〉, 〈bold〉764〈/bold〉, 156–166]. The final part of the data treatment chain, namely a novel multi‐dimensional refinement using a modified version of the 〈italic〉GSAS‐II〈/italic〉 software suite [〈ext-link ext-link-type="uri" xlink:href="http://scripts.iucr.org/cgi-bin/paper?aj5212"〉Toby & Von Dreele (2013). 〈italic〉J. Appl. Cryst.〈/italic〉〈bold〉46〈/bold〉, 544–549〈/ext-link〉], is compared with a standard data treatment of the same event data conventionally reduced as TOF diffraction patterns and refined with the unmodified version of 〈italic〉GSAS‐II〈/italic〉. This involves both determining the instrumental resolution parameters using POWGEN's powdered diamond standard sample and the refinement of a friendly‐user sample, BaZn(NCN)〈sub〉2〈/sub〉. Although each structural parameter on its own looks similar upon comparing the conventional (1D) and multi‐dimensional (2D) treatments, also in terms of precision, a closer view shows small but possibly significant differences. For example, the somewhat suspicious proximity of the 〈italic〉a〈/italic〉 and 〈italic〉b〈/italic〉 lattice parameters of BaZn(NCN)〈sub〉2〈/sub〉 crystallizing in 〈italic〉Pbca〈/italic〉 as resulting from the 1D refinement (0.008 Å) is five times less pronounced in the 2D refinement (0.038 Å). Similar features are found when comparing bond lengths and bond angles, 〈italic〉e.g.〈/italic〉 the two N—C—N units are less differently bent in the 1D results (173 and 175°) than in the 2D results (167 and 173°). The results are of importance not only for POWTEX but also for other neutron TOF diffractometers with large‐area detectors, like POWGEN at the SNS or the future DREAM beamline at the European Spallation Source.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The first real‐world neutron diffraction data have been collected with one of the POWTEX detectors (FRM II, Garching, Germany) mounted for testing at the Spallation Neutron Source (Oak Ridge National Laboratory, USA). They allow for angular‐ and wavelength‐dispersive Rietveld refinement using a modified version of 〈italic〉GSAS‐II〈/italic〉.〈boxed-text position="anchor" content-type="graphic" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:16005767:jcr2tu5033:jcr2tu5033-fig-0001"〉 〈/graphic〉〈/boxed-text〉〈/p〉
    Schlagwort(e): ddc:548 ; neutron detectors ; POWGEN beamline ; POWTEX detector ; DREAM beamline ; time‐of‐flight diffraction ; angular‐dispersive refinement ; wavelength‐dispersive refinement ; powder diffraction ; Rietveld refinement ; multi‐dimensional refinement
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 152
    facet.materialart.
    Unbekannt
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The paper by Gopalan [〈ext-link ext-link-type="uri" xlink:href="http://scripts.iucr.org/cgi-bin/paper?ib5086"〉(2020). 〈italic〉Acta Cryst.〈/italic〉 A〈bold〉76〈/bold〉, 318–327〈/ext-link〉] presented an enumeration of the 41 physical quantity types in non‐relativistic physics, in arbitrary dimensions, based on the formalism of Clifford algebra. Gopalan considered three antisymmetries: spatial inversion, 〈overline〉1〈/overline〉, time reversal, 1′, and wedge reversion, 1〈sup〉†〈/sup〉. A consideration of the set of all seven antisymmetries (〈overline〉1〈/overline〉, 1′, 1〈sup〉†〈/sup〉, 1′〈sup〉†〈/sup〉, 〈overline〉1〈/overline〉〈sup〉†〈/sup〉, 〈overline〉1〈/overline〉′, 〈overline〉1〈/overline〉′〈sup〉†〈/sup〉) leads to an extension of the results obtained by Gopalan. It is shown that there are 51 types of physical quantities with distinct symmetry properties in total.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉It is shown that there are 51 types of physical quantities in arbitrary dimensions with distinct transformations by wedge reversion symmetry. In the paper by 〈ext-link ext-link-type="uri" xlink:href="http://scripts.iucr.org/cgi-bin/paper?ib5086"〉Gopalan [(2020). 〈italic〉Acta Cryst.〈/italic〉 A〈bold〉76〈/bold〉, 318–327]〈/ext-link〉 only 41 types were enumerated.〈boxed-text position="anchor" content-type="graphic" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:20532733:aya2ib5117:aya2ib5117-fig-0001"〉 〈alt-text〉image〈/alt-text〉 〈/graphic〉〈/boxed-text〉〈/p〉
    Schlagwort(e): ddc:548 ; multivectors ; wedge reversion ; antisymmetry ; Clifford algebra
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 153
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉A seismic swarm affected the 53.3°–54.3° Latitude North section of the Mid‐Atlantic Ridge from 26 September to 10 December 2022. We rely on regional, teleseismic and array data to relocate 61 hypocenters and derive 77 moment tensors. The 2022 swarm released a cumulative moment equivalent to Mw 6.3. Seismicity was shallow (7 ± 3 km depth). Most earthquakes are located along the ridge axis with typical, NS oriented normal faulting mechanisms, but a few among the largest and latest earthquakes have unusual thrust mechanisms and locations as far as ∼25 km from the ridge. We attribute the swarm to a shallow magmatic intrusion, with a vertical dike first propagating ∼60 km along axis, accompanied by shallow normal faulting, and then thickening and triggering thrust earthquakes off the ridge, in response to compressive stress buildup. The unrest provides a rare example of an energetic, magmatic driven swarm episode at the mid‐ocean ridge.〈/p〉
    Beschreibung: Plain Language Summary: The largest plate boundary systems on Earth are Mid‐ocean ridges (MOR), where the plates continuously drift apart and new lithosphere is constantly being formed. Although the process is well understood, we rarely detect spreading events at MOR, mainly because these regions are remote and local monitoring is rarely possible. In September–November 2022 a large, unusual seismic swarm occurred along a spreading center ridge segment of the North Mid‐Atlantic Ridge. Despite the remoteness of the region, we managed to model regional and teleseismic data to perform earthquake relocation, depth estimation and moment tensor inversion. In this way, we could reconstruct the geometry and the evolution of the seismicity. We found that in the early days of the swarm, seismicity migrated unilaterally over ∼60 km along the ridge axis, from North to South, triggering normal faulting earthquakes, which are typical at MOR. Later, large thrust mechanisms, anomalous in an extensional environment, appeared and quickly became predominant. We explain seismological observations by a magmatic intrusion, which first propagated southward, producing shallow normal faulting earthquakes above the vertical magma dike, and later thickened, increasing compressional stresses on its sides, and triggering large thrust earthquakes.〈/p〉
    Beschreibung: Key Points: Analysis of a short, intense seismic swarm at the Mid‐Atlantic Ridge. Identification of unusual, thrust focal mechanisms in an extensional environment. Swarm triggered by dike intrusion at the mid‐ocean ridge.
    Beschreibung: German BMBF project EWRICA
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: https://doi.org/10.5281/zenodo.8089070
    Schlagwort(e): ddc:551.22 ; seismic swarm ; Mid‐Atlantic Ridge ; seismicity ; magma dyke
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 154
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉We present the results of salinity (ΔS) and temperature (ΔT) anomalies in the sea surface microlayer (SML) in relation to the underlying mixed bulk water (bulk). Several light to moderate rain events were recorded in the southern Pacific near Fiji using our remotely operated catamaran. Precipitation and evaporation drive freshwater fluxes across the sea surface (i.e., the SML) and are the most essential processes of the hydrologic cycle. However, measurements of the SML during precipitation are rare, but necessary to fully understand freshwater exchange at the air‐sea interface. Here we show that freshwater can mix rapidly with the bulk water through wind‐induced mixing, as ΔS and ΔT show a clear dependence on wind speed. At high wind speeds (5.1–11.6 m s〈sup〉−1〈/sup〉), anomalies approach zero (ΔS = −0.02 ± 0.49 g kg〈sup〉−1〈/sup〉, ΔT = −0.09 ± 0.46°C) but can reach ΔS = 1.00 ± 0.20 g kg〈sup〉−1〈/sup〉 and ΔT = −0.37 ± 0.09°C at lower wind speeds (0–2 m s〈sup〉−1〈/sup〉). We find shallow freshwater lenses and fronts, likely caused by past rainfall, with ΔS and ΔT of up to −1.11 g kg〈sup〉−1〈/sup〉 and 1.77°C, respectively. Our observations suggest that freshwater lenses can be very shallow (〈1 m depth) and missed by conventional measurements. In addition, the temperature and salinity in the SML respond to freshwater fluxes instantaneously. It highlights the role of the SML in a mechanistic understanding of the fate of freshwater over the ocean and, therefore, the global hydrologic cycle.〈/p〉
    Beschreibung: Plain Language Summary: Rain and evaporation are the most important processes in the global water cycle, causing either the supply to or the removal of freshwater from the upper ocean, thereby changing the salinity of the sea surface. Evaporation also removes heat and lowers the temperature on the ocean surface. We used the measurements of sea surface microlayer (SML) salinity and temperature as key indicators to study hydrologic cycle processes during our cruise with the RV Falkor in the South Pacific and found that freshwater mixes rapidly with the underlying bulk water during strong winds (5.1–11.6 m s〈sup〉−1〈/sup〉). We also detected shallow freshwater lenses and fronts, most likely caused by past rainfall, with ΔS and ΔT of up to −1.11 g kg〈sup〉−1〈/sup〉 and 1.77°C, respectively. Our observations suggest that freshwater lenses can occur at the sea surface and that the SML respond to freshwater fluxes instantaneously. It highlights the role of the SML for future studies of the global hydrologic cycle.〈/p〉
    Beschreibung: Key Points: Small scale air‐sea interactions (freshwater fluxes) during precipitation were investigated in the southern Pacific. Temperature and salinity anomalies occur with a high spatial variability.Measurements with remote controlled catamaran revealed shallow freshwater lenses, which were not detectable with ship based measurements.
    Beschreibung: German Research Foundation
    Beschreibung: https://doi.org/10.7284/908805
    Beschreibung: https://www.rvdata.us/search/cruise/FK191120
    Beschreibung: https://bec.icm.csic.es/
    Beschreibung: https://smos-diss.eo.esa.int/
    Beschreibung: https://doi.org/10.48670/moi-00165
    Beschreibung: https://disc.gsfc.nasa.gov/datasets/GPM_3IMERGHH_06/summary
    Schlagwort(e): ddc:551.46 ; salinity and temperature anomalies ; sea surface microlayer ; freshwater fluxes ; global hydrologic cycle ; research catamaran
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 155
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Benthic oxygen dynamics and the exchange of oxygen and other solutes across the sediment‐water interface play a key role for the oxygen budget of many limnic and shallow marine systems. The sediment‐water fluxes are largely determined by two factors: sediment biogeochemistry and the thickness of the diffusive boundary layer that is determined by near‐bottom turbulence. Here, we present a fully coupled benthic‐pelagic modeling system that takes these processes and their interaction into account, focusing especially on the modulation of the sediment‐water fluxes by the effects of near‐bottom turbulence and stratification. We discuss the special numerical methods required to guarantee positivity and mass conservation across the sediment‐water interface in the presence of rapid element transformation, and apply this modeling system to a number of idealized scenarios. Our process‐oriented simulations show that near‐bottom turbulence provides a crucial control on the sediment‐water fluxes, the oxygen penetration depth, and the re‐oxidation of reduced compounds diffusing upward from the deeper benthic layers especially on time scales of a few days, characterizing oceanic tides, internal seiching motions in lakes, and mesoscale atmospheric variability. Our results also show that the response of benthic‐pelagic fluxes to rapid changes in the forcing conditions (e.g., storm events) can only be understood with a fully coupled modeling approach.〈/p〉
    Beschreibung: Plain Language Summary: Oxygen is one of the most relevant ecosystem parameters in marine systems and in lakes. In shallow systems, the overall oxygen budget is often controlled by the sedimentary oxygen demand, and it is therefore crucial to account for the exchange of oxygen and other solutes between the sediment and the water column. In this, context, a thin (millimeter‐scale) “diffusive sublayer,” located immediately above the sediment surface, is known to play an especially important role as it may form a bottleneck for the solute exchange. As the thickness of this sublayer is controlled by hydrodynamic processes, sediment‐water fluxes are affected by complex feedbacks between physical and biogeochemical processes. Here, we describe a fully coupled numerical modeling system that takes these feedback mechanisms into account, including advanced numerical methods guaranteeing that the total mass of all solutes is conserved (even if these are transformed) and that their concentrations do not become negative. Using a series of idealized examples, it is shown that near‐bottom hydrodynamic processes have an important impact on the sediment‐water fluxes, the depth to which oxygen penetrates into the upper sediment layers, and the re‐oxidation of reduced chemical compounds in the sediments. These feedbacks are particularly important for processes with time scales of a few days, like ocean tides, internal oscillations in lakes, and short‐term atmospheric disturbances (e.g., storm events).〈/p〉
    Beschreibung: Key Points: First fully coupled benthic‐pelagic modeling system accounting for the effects of near‐bottom turbulence on sediment‐water solute fluxes. Hydrodynamic effects control benthic biogeochemistry and fluxes especially on time scales of a few days, and during extreme events. New numerical methods that guarantee mass conservation and positivity across the sediment‐water interface.
    Beschreibung: Leibniz Association
    Beschreibung: German Research Foundation
    Beschreibung: Swiss National Science Foundation
    Beschreibung: UK Natural Environment Research Council
    Beschreibung: Department for Environment Food and Rural Affairs
    Beschreibung: https://gotm.net/
    Beschreibung: https://github.com/fabm-model
    Beschreibung: https://doi.org/10.5281/zenodo.7950383
    Beschreibung: https://doi.org/10.5281/zenodo.7950866
    Schlagwort(e): ddc:550 ; sediment-water fluxes ; benthic biogeochemistry ; numerical modeling
    Sprache: Englisch
    Materialart: doc-type:article
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  • 156
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Freshwater biodiversity, from fish to frogs and microbes to macrophytes, provides a vast array of services to people. Mounting concerns focus on the accelerating pace of biodiversity loss and declining ecological function within freshwater ecosystems that continue to threaten these natural benefits. Here, we catalog nine fundamental ecosystem services that the biotic components of indigenous freshwater biodiversity provide to people, organized into three categories: material (food; health and genetic resources; material goods), non‐material (culture; education and science; recreation), and regulating (catchment integrity; climate regulation; water purification and nutrient cycling). If freshwater biodiversity is protected, conserved, and restored in an integrated manner, as well as more broadly appreciated by humanity, it will continue to contribute to human well‐being and our sustainable future via this wide range of services and associated nature‐based solutions to our sustainable future.〈/p〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉
    Beschreibung: María de Maeztu excellence accreditation 2018‐2022
    Beschreibung: Ministerio de Ciencia e Innovación (MCIN) http://dx.doi.org/10.13039/501100004837
    Beschreibung: Leibniz Competition: Freshwater Megafauna Futures
    Beschreibung: CGIAR Initiative on NEXUS Gains
    Schlagwort(e): ddc:333.9 ; ecosystem services ; freshwater biodiversity ; freshwater ecosystems ; freshwater life
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 157
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉ABSTRACT〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Reconstruction of mass accumulation rates (MARs) in loess deposits are widely used for interpreting long‐term aeolian transport and climate dynamics in terrestrial environments. However, these interpretations are often driven by a preponderance of reconstructions from individual or selected sites, which can bias our understanding of past climate, especially in the absence of other proxy information. Recent studies on MARs from multiple loess sites in Arid Central Asia (ACA) reveal disparities in the timing of peaks in accumulation between sites, as well as asynchronies with loess flux in the Chinese Loess Plateau (CLP). We investigate this issue by (1) dating five new sites from the western Ili Basin, therefore extending the spatial cover of loess chronologies across ACA and (2) combining that with MARs from >30 sites across ACA and the CLP over the last 60 ka. Our results indicate spatio‐temporal inhomogeneity in the timing and rate of loess deposition across the ACA, and highlight the importance of interrogating local and regional influences on dust supply and transport. Our synthesis of MARs from ACA and the CLP suggests that the timing of peak dust flux as an indicator of large‐scale climate dynamics is best derived from an aggregate of sites; this removes site‐specific bias where local processes or topographic settings outweigh the climate signature.〈/p〉
    Beschreibung: L Lisá acknowledges the support of internal program No. RVO67985831 of the Institute of Geology CAS, Prague and OP RDE, MEYS under the project ‘Ultra‐trace isotope research in social and environmental studies using accelerator mass spectrometry’, Reg. No. CZ.02.1.01/0.0/0.0/16_019/0000728.
    Beschreibung: This study was funded by an independent Max Planck Research Group awarded by the Max Planck Society to KE Fitzsimmons.
    Schlagwort(e): ddc:551.3 ; ddc: ; Central Asia ; Chinese Loess Plateau ; loess ; luminescence dating ; mass accumulation rates
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 158
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The processing of aerosol by droplet collision‐coalescence is analyzed in three‐dimensional simulations of drizzling stratocumulus using a Lagrangian cloud model for the representation of aerosol and cloud microphysics. Collision‐coalescence processing is shown to create a characteristic bimodality in the aerosol size distribution. We show that the large‐scale dynamics of the stratocumulus‐topped boundary layer are key to understanding the amount of time available for collision‐coalescence processing. The large‐scale dynamics enable aerosol particles to repeat a cycle of droplet condensation, collision‐coalescence, and evaporation, which causes a steady increase in aerosol size. This process is continued until the aerosol grows so large that droplet growth is substantially accelerated and multiple collisions occur within one cycle, forming precipitation‐sized droplets that are lost to the surface, including the aerosol. An analytical relationship is derived that captures the fundamental shape of the processed aerosol size distribution.〈/p〉
    Beschreibung: Plain Language Summary: Clouds consist of cloud droplets, and cloud droplets grow from aerosol particles, which are tiny particles suspended in the atmosphere. But clouds also modify aerosol particles. This study shows that the merging of cloud droplets, a process related to the production of rain, can lead to larger aerosol particles, causing characteristic changes in the aerosol size distribution that are revealed in this study. These changes are important because larger aerosol particles will create cloud droplets more easily, with commensurate effects on the development of clouds.〈/p〉
    Beschreibung: Key Points: The effect of droplet collision‐coalescence on the aerosol size distribution is analyzed in three‐dimensional simulations. Collision‐coalescence processing introduces a characteristic bimodality in the aerosol size distribution. The large‐scale stratocumulus dynamics are key to the development of a stable population of processed aerosol particles.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Climate Program Office http://dx.doi.org/10.13039/100007298
    Beschreibung: National Science Foundation http://dx.doi.org/10.13039/100000001
    Beschreibung: http://rossby.msrc.sunysb.edu/SAM.html
    Beschreibung: https://doi.org/10.5281/zenodo.7734008
    Schlagwort(e): ddc:551.5 ; clouds ; aerosol ; processing ; collision
    Sprache: Englisch
    Materialart: doc-type:article
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  • 159
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Regional assessments of the wind erosion risk are rare and vary due to the methods used and the available data to be included. The adaptation of existing methods has the advantage that the results can be compared directly. We adopted an already successfully applied methodology (ILSWE—applied in East Africa), to investigate the spatiotemporal variability of the wind erosion risk between 2005 and 2019 in Southern Africa. The approach integrates climatic variables, a vegetation index, and soil properties to describe the potential impact of wind erosion at the landscape scale. The annual and seasonal variability is determined by the vegetation cover, whereas droughts and strong El Niño events had only regional effects. We estimated that 8.3% of the study area experiences a moderate to elevated wind erosion risk over the 15‐year period with annual and inter‐annual fluctuations showing a slight upward trend. In general, the desert and drylands in the west have the highest proportion of risk areas, the moist forests in the east are characterized by a very low risk of wind erosion, while the grasslands, shrublands, and croplands in the interior most likely react to changes of climatic conditions. The validation process is based on a comparison with the estimated frequency of dust storms derived from the aerosol optical depth and angstrom exponent and revealed an overall accuracy of 65%. The results of this study identify regions and yearly periods prone to wind erosion to prioritize for further analysis and conservation policies for mitigation and adaptation strategies.〈/p〉
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: German Federal Ministry of Education and Research (BMBF)
    Beschreibung: http://www.climatologylab.org/terraclimate
    Beschreibung: https://www.isric.org/
    Beschreibung: http://www.fao.org/soils-portal/data-hub/soil-maps-and-databases/harmonized-world-soil-database-v12
    Beschreibung: https://land.copernicus.eu/global/products/fcover
    Beschreibung: https://www.esa-landcover-cci.org/%20
    Beschreibung: https://databasin.org/
    Beschreibung: https://giovanni.gsfc.nasa.gov/giovanni/
    Schlagwort(e): ddc:551.3 ; environmental modelling ; geographic information systems ; ILSWE model ; remote sensing ; temporal variability ; wind erosion
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 160
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉We used the tropospheric and lower stratospheric 3D winds for four consecutive years (2017–2020) to study the momentum flux (MF) and vertical wind power spectra (VWP) over Andøya, Norway (69.30°N, 16.04°E) using the Middle Atmosphere Alomar Radar System. The spectra range from 3.5 days〈sup〉−1〈/sup〉 > 〈italic〉f〈/italic〉 > 30 min〈sup〉−1〈/sup〉, which are categorized in terms of observed/ground‐based frequency (as the local inertial period is 13 h over Andøya), height ranges, and seasons. Our results indicate for the first time that (a) both the zonal and meridional MF display peaks around the inertial period (13 h) in the troposphere (1.80–12.00 km) during all seasons (with some exceptions), while VWP exhibits such features in the whole height range (1.80–18.00 km), (b) the minimum variability in MF, VWP, and kinetic energy is observed during summer, and (c) both the MF and VWP demonstrate height variation with maximum deviations below the tropopause.〈/p〉
    Beschreibung: Plain Language Summary: The wind measurements are used to study the height and seasonal variation of momentum flux and vertical wind power spectra during 2017–2020. We report for the first time that both the momentum flux and vertical wind power spectra depict more variations in the tropospheric heights (around 1.80–7.20 km), below the tropopause, with the minimum amplitudes in the summer months (June–July–August). Moreover, long‐period oscillations have more energy than short‐period oscillations, and therefore, contribute more to the energy or flux transfer from the lower to the higher atmosphere. The month versus height profile of kinetic energy also portrays a similar feature with considerably more magnitude for the long‐period oscillations than the short‐period ones. The kinetic energy displays an enhancement of magnitude near the tropopause (∼5.00–10.00 km).〈/p〉
    Beschreibung: Key Points: The zonal and meridional momentum flux spectra exhibit a peak around the inertial period of 13 h in the troposphere (1.80–12.00 km). Height profiles of momentum flux, vertical wind power spectra, and kinetic energy display seasonal variation with a minimum during summer. The maximum variability of momentum flux and vertical wind power spectra is noticed below tropopause and decreases with increasing height.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347
    Beschreibung: https://doi.org/10.22000/766
    Schlagwort(e): ddc:551.5 ; atmospheric gravity waves ; momentum flux ; power spectra ; kinetic energy
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 161
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The market for electric vehicles is growing rapidly, and there is a large demand for lithium‐ion batteries (LIB). Studies have predicted a growth of 600% in LIB demand by 2030. However, the production of LIBs is energy intensive, thus contradicting the goal set by Europe to reduce greenhouse gas (GHG) emissions and become GHG emission free by 2040. Therefore, in this study, it was analyzed how the energy consumption and corresponding GHG emissions from LIB cell production may develop until 2030. Economic, technological, and political measures were considered and applied to market forecasts and to a model of a state‐of‐the art LIB cell factory. Notably, different scenarios with trend assumptions and above/below‐trend assumptions were considered. It could be deduced that, if no measures are taken and if the status quo is extrapolated to the future, by 2030, ∼5.86 Mt CO〈sub〉2〈/sub〉‐eq will be emitted due to energy consumption from European LIB cell production. However, by applying a combination of economic, technological, and political measures, energy consumption and GHG emissions could be decreased by 46% and 56% by 2030, respectively. Furthermore, it was found that political measures, such as improving the electricity mix, are important but less dominant than improving the production technology and infrastructure. In this study, it could be deduced that, by 2030, through industrialization and application of novel production technologies, the energy consumption and GHG emissions from LIB cell production in Europe can be reduced by 24%.〈/p〉
    Beschreibung: German Federal Ministry of Education and Research
    Schlagwort(e): ddc:363.7 ; battery cell production ; energy consumption ; forecast ; greenhouse gas emissions ; industrial ecology ; technology assessment
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 162
    Publikationsdatum: 2023-07-21
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Governments commit to ensuring the welfare of their citizens by drafting and enforcing regulations that ultimately ensure the sustainability of mining. This study contributes to improving the sustainability of mining throughout the mine's lifecycle until the final destination of the mining products. We propose recommendations that address the sustainability of mining from a global perspective, framed around the United Nations Sustainable Development Goals (SDGs), following waste hierarchy with Common Agricultural Policies, and policies from the Green Deal on climate, energy, transport, and taxation. Tailings are the most significant source of environmental impact in mining operations and, therefore, must comply with controlling regulations through Tailings Management Facilities (TMFs). However, there have been several mining accidents involving TMFs worldwide. The recommendations begin during planning, preconstruction, and construction with practices such as fair consultations, tax revenue fairness, and mandatory insurance. The operation and management support parallel industries to mining and supporting health and education. Emergency planning involves the surrounding communities in mock drills and environmental monitoring. In the closure and rehabilitation, remediation technologies such as phytoremediation, carbon sequestration incentives, and biomass valorization are recommended. Finally, supporting a circular economy by prioritizing ethical consumption, resource reduction, material recovery, and replacing toxic minerals and materials from the start with “benign by design” is recommended. The strategies involve stakeholders directly or indirectly related to the mining companies' contamination and demonstrate a commitment to the SDGs, offering a holistic perspective on scientific, social, and regulatory issues. 〈italic〉Integr Environ Assess Manag〈/italic〉 2023;19:949–960. © 2023 The Authors. 〈italic〉Integrated Environmental Assessment and Management〈/italic〉 published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).〈/p〉
    Beschreibung: Key Points:This study addresses the sustainability of mining, to be implemented throughout the life cycle of a mine until the final destination of the products from mining. Policymakers should prioritize the implementation of sustainable mining practices that align with the Sustainable Development Goals, waste hierarchy, and policies from the Green Deal to ensure the long‐term viability of the industry and protect the environment and communities. We make recommendations that address the whole mining process, offering a holistic perspective on scientific, social, and regulatory issues.
    Beschreibung: https://doi.org/10.6084/m9.figshare.19401011.v5
    Schlagwort(e): ddc:622 ; Biomass valorization ; Community involvement ; Mining ; Risk management ; Tailing Mining Facilities
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 163
    Publikationsdatum: 2023-07-25
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Many operational weather services use ensembles of forecasts to generate probabilistic predictions. Computational costs generally limit the size of the ensemble to fewer than 100 members, although the large number of degrees of freedom in the forecast model would suggest that a vastly larger ensemble would be required to represent the forecast probability distribution accurately. In this study, we use a computationally efficient idealised model that replicates key properties of the dynamics and statistics of cumulus convection to identify how the sampling uncertainty of statistical quantities converges with ensemble size. Convergence is quantified by computing the width of the 95% confidence interval of the sampling distribution of random variables, using bootstrapping on the ensemble distributions at individual time and grid points. Using ensemble sizes of up to 100,000 members, it was found that for all computed distribution properties, including mean, variance, skew, kurtosis, and several quantiles, the sampling uncertainty scaled as 〈mml:math id="jats-math-1" display="inline" overflow="scroll"〉〈mml:msup〉〈mml:mrow〉〈mml:mi〉n〈/mml:mi〉〈/mml:mrow〉〈mml:mrow〉〈mml:mo form="prefix"〉−〈/mml:mo〉〈mml:mn〉1〈/mml:mn〉〈mml:mo stretchy="false"〉/〈/mml:mo〉〈mml:mn〉2〈/mml:mn〉〈/mml:mrow〉〈/mml:msup〉〈/mml:math〉 for sufficiently large ensemble size 〈mml:math id="jats-math-2" display="inline" overflow="scroll"〉〈mml:mrow〉〈mml:mi〉n〈/mml:mi〉〈/mml:mrow〉〈/mml:math〉. This behaviour is expected from the Central Limit Theorem, which further predicts that the magnitude of the uncertainty depends on the distribution shape, with a large uncertainty for statistics that depend on rare events. This prediction was also confirmed, with the additional observation that such statistics also required larger ensemble sizes before entering the asymptotic regime. By considering two methods for evaluating asymptotic behaviour in small ensembles, we show that the large‐〈mml:math id="jats-math-3" display="inline" overflow="scroll"〉〈mml:mrow〉〈mml:mi〉n〈/mml:mi〉〈/mml:mrow〉〈/mml:math〉 theory can be applied usefully for some forecast quantities even for the ensemble sizes in operational use today.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉An idealised ensemble that replicates key properties of the dynamics and statistics of cumulus convection is used to identify how sampling uncertainty of statistical quantities converges with ensemble size. A universal asymptotic scaling for this convergence was found, which was dependent on the statistic and the distribution shape, with largest uncertainty for statistics that depend on rare events. This is demonstrated in the figure below for a Gaussian distributed model variable, where the sampling uncertainty (y‐axis) for 5 quantiles (red lines) indicates that after a certain ensemble size, it begins converging asymptotically (grey lines), and the more extreme the quantile, the more members it requires for this to be the case. 〈boxed-text position="anchor" id="qj4410-blkfxd-0001" content-type="graphic" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:00359009:media:qj4410:qj4410-toc-0001"〉
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Klaus Tschira Stiftung http://dx.doi.org/10.13039/501100007316
    Schlagwort(e): ddc:551.6 ; asymptotic convergence ; distributions ; ensembles ; idealised model ; sampling uncertainty ; weather prediction
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 164
    Publikationsdatum: 2023-07-25
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉We provide a review of micropalaeontological research on Ostracoda from the Middle Pleistocene (MIS 11, Holstein interglacial) hominin site Bilzingsleben in Thuringia in Central Germany from 1963 to the 1990s. Samples from four sections inside and six search pits outside the excavation area were investigated and, in total, 49 ostracod species were identified. The ostracod assemblages of the sections mirror the complex and small‐scale palaeoenvironmental evolution of the site from a seeping‐spring to fluviatile, lacustrine and finally seeping‐spring habitat in which a massive tufa layer formed and prevented erosion of the sediments beneath. Pleistocene index fossils are represented by 〈italic〉Ilyocypris quinculminata〈/italic〉 from search pit 3/sample 9933 and 〈italic〉Scottia browniana〈/italic〉 from section 70. Both species indicate the age dating of MIS 11 for the tufa deposit. The results of this study facilitate new insights into site formation processes, enable refinement of the interpretation of the archaeological record and shed light on the question: Does the find‐bearing layer at the Bilzingsleben site contain in situ remains of a camp site of 〈italic〉Homo erectus〈/italic〉 or not? Our results suggest that the site is not unaffected at least.〈/p〉
    Beschreibung: Free State of Thuringia
    Schlagwort(e): ddc:565 ; actualistic approach ; Holstein interglacial ; Ostracoda ; palaeo air temperature ; palaeosalinity ; tufa
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 165
    Publikationsdatum: 2023-07-25
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Local ensemble transform Kalman filters (LETKFs) allow explicit calculation of the Kalman gain, and by this the contribution of individual observations to the analysis field. Though this is a known feature, the information on the analysis contribution of individual observations (partial analysis increment) has not been used as systematic diagnostic up to now despite providing valuable information. In this study, we demonstrate three potential applications based on partial analysis increments in the regional modelling system of Deutscher Wetterdienst and propose their use for optimising LETKF data assimilation systems, in particular with respect to satellite data assimilation and localisation. While exact calculation of partial analysis increments would require saving the large, five‐dimensional ensemble weight matrix in the analysis step, it is possible to compute an approximation from standard LETKF output. We calculate the Kalman gain based on ensemble analysis perturbations, which is an approximation in the case of localisation. However, this only introduces minor errors, as the localisation function changes very gradually among nearby grid points. On the other hand, the influence of observations always depends on the presence of other observations and settings for the observation error and for localisation. However, the influence of observations behaves approximately linearly, meaning that the assimilation of other observations primarily decreases the magnitude of the influence, but it does not change the overall structure of the partial analysis increments. This means that the calculation of partial analysis increments can be used as an efficient diagnostic to investigate the three‐dimensional influence of observations in the assimilation system. Furthermore, the diagnostic can be used to detect whether the influence of additional experimental observations is in accordance with other observations without conducting computationally expensive single‐observation experiments. Last but not least, the calculation can be used to approximate the influence an observation would have when applying different assimilation settings.〈/p〉
    Schlagwort(e): ddc:551.5 ; analysis influence ; convective‐scale ; ensemble data assimilation ; localisation ; NWP ; satellite data assimilation
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 166
    Publikationsdatum: 2023-07-25
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉For both the meso‐ and synoptic scales, reduced mathematical models give insight into their dynamical behaviour. For the mesoscale, the weak temperature gradient approximation is one of several approaches, while for the synoptic scale the quasigeostrophic theory is well established. However, the way these two scales interact with each other is usually not included in such reduced models, thereby limiting our current perception of flow‐dependent predictability and upscale error growth. Here, we address the scale interactions explicitly by developing a two‐scale asymptotic model for the meso‐ and synoptic scales with two coupled sets of equations for the meso‐ and synoptic scales respectively. The mesoscale equations follow a weak temperature gradient balance and the synoptic‐scale equations align with quasigeostrophic theory. Importantly, the equation sets are coupled via scale‐interaction terms: eddy correlations of mesoscale variables impact the synoptic potential vorticity tendency and synoptic variables force the mesoscale vorticity (for instance due to tilting of synoptic‐scale wind shear). Furthermore, different diabatic heating rates—representing the effect of precipitation—define different flow characteristics. With weak mesoscale heating relatable to precipitation rates of 〈mml:math id="jats-math-1" display="inline" overflow="scroll"〉〈mml:mrow〉〈mml:mi〉𝒪〈/mml:mi〉〈mml:mo stretchy="false"〉(〈/mml:mo〉〈mml:mn〉6〈/mml:mn〉〈mml:mspace width="0.3em"/〉〈mml:mtext〉mm〈/mml:mtext〉〈mml:mo〉·〈/mml:mo〉〈mml:msup〉〈mml:mrow〉〈mml:mi mathvariant="normal"〉h〈/mml:mi〉〈/mml:mrow〉〈mml:mrow〉〈mml:mo form="prefix"〉−〈/mml:mo〉〈mml:mn〉1〈/mml:mn〉〈/mml:mrow〉〈/mml:msup〉〈mml:mo stretchy="false"〉)〈/mml:mo〉〈/mml:mrow〉〈/mml:math〉, the mesoscale dynamics resembles two‐dimensional incompressible vorticity dynamics and the upscale impact of the mesoscale on the synoptic scale is only of a dynamical nature. With a strong mesosocale heating relatable to precipitation rates of 〈mml:math id="jats-math-2" display="inline" overflow="scroll"〉〈mml:mrow〉〈mml:mi〉𝒪〈/mml:mi〉〈mml:mo stretchy="false"〉(〈/mml:mo〉〈mml:mn〉60〈/mml:mn〉〈mml:mspace width="0.3em"/〉〈mml:mtext〉mm〈/mml:mtext〉〈mml:mo〉·〈/mml:mo〉〈mml:msup〉〈mml:mrow〉〈mml:mi mathvariant="normal"〉h〈/mml:mi〉〈/mml:mrow〉〈mml:mrow〉〈mml:mo form="prefix"〉−〈/mml:mo〉〈mml:mn〉1〈/mml:mn〉〈/mml:mrow〉〈/mml:msup〉〈mml:mo stretchy="false"〉)〈/mml:mo〉〈/mml:mrow〉〈/mml:math〉, divergent motions and three‐dimensional effects become relevant for the mesoscale dynamics and the upscale impact also includes thermodynamical effects.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉We develop a two‐scale asymptotic model for the meso‐ and synoptic scales following a weak temperature gradient balance and quasigeostrophic theory, but with explicit scale interactions and dependent on the mesoscale diabatic heating. With weak mesoscale heating, the mesoscale dynamics resembles 2D incompressible vorticity dynamics and the upscale impact on the synoptic scale is only of a dynamical nature. With strong mesoscale heating, divergent motions and 3D effects become relevant for the mesoscale and the upscale impact also includes thermodynamical effects. 〈boxed-text position="anchor" id="qj4456-blkfxd-0001" content-type="graphic" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:00359009:media:qj4456:qj4456-toc-0001"〉
    Beschreibung: German Research Foundation (DFG)
    Schlagwort(e): ddc:551.5 ; asymptotics ; atmospheric dynamics ; mesoscale ; multiscale scale interactions ; quasigeostrophic ; synoptic scale
    Sprache: Englisch
    Materialart: doc-type:article
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  • 167
    Publikationsdatum: 2023-07-26
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Aquatic ecosystems play an important role in global methane cycling and many field studies have reported methane supersaturation in the oxic surface mixed layer (SML) of the ocean and in the epilimnion of lakes. The origin of methane formed under oxic condition is hotly debated and several pathways have recently been offered to explain the “methane paradox.” In this context, stable isotope measurements have been applied to constrain methane sources in supersaturated oxygenated waters. Here we present stable carbon isotope signatures for six widespread marine phytoplankton species, three haptophyte algae and three cyanobacteria, incubated under laboratory conditions. The observed isotopic patterns implicate that methane formed by phytoplankton might be clearly distinguished from methane produced by methanogenic archaea. Comparing results from phytoplankton experiments with isotopic data from field measurements, suggests that algal and cyanobacterial populations may contribute substantially to methane formation observed in the SML of oceans and lakes.〈/p〉
    Beschreibung: Plain Language Summary: Methane plays an important role in atmospheric chemistry and physics as it contributes to global warming and to the destruction of ozone in the stratosphere. Knowing the sources and sinks of methane in the environment is a prerequisite for understanding the global atmospheric methane cycle but also to better predict future climate change. Measurements of the stable carbon isotope composition of carbon—the ratio between the heavy and light stable isotope of carbon—help to identify methane sources in the environment and to distinguish them from other formation processes. We identified the carbon isotope fingerprint of methane released from phytoplankton including algal and cyanobacterial species. The observed isotope signature improves our understanding of methane cycling in the surface layers of aquatic environments helping us to better estimate methane emissions to the atmosphere.〈/p〉
    Beschreibung: Key Points: Stable carbon isotope values of methane emitted from six phytoplankton cultures incubated in the laboratory. Isotope fractionation between methane source signature and biomass of widespread algal and cyanobacterial species. Isotopic patterns of methane released by phytoplankton may be clearly distinguished from methane formed by methanogenic archaea.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: Spanish Ministry of Universities
    Beschreibung: https://doi.org/10.11588/data/YYLEKU
    Schlagwort(e): ddc:551.9 ; methane ; stable isotopes ; phytoplankton ; algae ; cyanobacteria ; methane paradox
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 168
    Publikationsdatum: 2023-01-05
    Beschreibung: Nachdem sich Herzog Georg von Sachsen mit den Problemen des Bergbaus auf dem Aldenberg und Geising auseinandergesetzt hatte, erlies er am 11. November 1489 eine Ordnung für die dortigen Bergwerke. In den acht Artikeln dieser Ordnung wurden die Entlohnung der Bergleute sowie die Pflichten der Hutleute, Mühlmeister, Schmelzer und die Strafen bei Zuwiderhandlung festgelegt. Weiterhin wurde eine Vereidigung der Hutleute, Mühlenmeister und Schmelzer befohlen.
    Beschreibung: source
    Schlagwort(e): Herzog Georg von Sachsen ; Herzog Albrecht von Sachsen ; Hans von Bärenstein zu Ottendorf ; Altenberg ; Geising ; Zinnbergbau ; Sachsen ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 6
    Standort Signatur Erwartet Verfügbarkeit
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  • 169
    Publikationsdatum: 2023-01-11
    Beschreibung: Diese Bergordnung wurde am 7. Januar 1474 für die Bergwerke in Schwaz von Herzog Siegmund von Österreich erlassen. Mit dem ab 1470 stark ansteigenden Bergbauaktivitäten kam es gleichzeitig zu zahlreichen Missständen bei der Dienstdurchführung der Hutleute sowie zu offensichtlich chaotischen Zuständen bei der Vermessung der Grubenfelder. In 16 Paragrafen wurden deshalb die Rechte der Gruben an ihren Feldern, das ordentliche Vermessen der Grubenfelder und das Verhalten bei Durchschlägen beschrieben sowie die Zuständigkeiten der Hutleute klar benannt. In einem später eingefügten Zusatz wurde das Fällen von Bäumen im gesamten Bergbaubezirk verboten.
    Beschreibung: source
    Schlagwort(e): Herzog Siegmund von Österreich ; Österreich ; Tirol ; Schwaz ; Freundsberg, Burg ; Schlitters ; Innsbruck ; Silberbergbau ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 7
    Standort Signatur Erwartet Verfügbarkeit
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  • 170
    facet.materialart.
    Unbekannt
    Publikationsdatum: 2023-03-06
    Beschreibung: Diese Bergordnung wurde von den Räten der sieben wichtigsten Bergstädte des Bergbaureviers Zips in bei einer Zusammenkunft in Kaschau (Košice) am 26. und 27. Dezember 1487 erlassen. Es wurde vereinbart, das ein getroffener Rechtsspruch in einer der Städte fortan auch für die anderen Städte gelten soll. Dabei waren das Gericht und der Rat der Stadt Göllnitz die erste Instanz. In der Rechtssatzung wurden die Zuständigkeit der Rechtsprechung durch die Bergmeister und die Rechte der Arbeiter bei der Lohnzahlung definiert. Eindeutig wurde darauf verwiesen, dass die genannten Bergstädte nicht gleichberechtigt sind und deren Rangfolge aufgeführt. An erster Stelle stand Göllnitz (Gelnica), gefolgt von Schmöllnitz (Smolník), Ruda (Rudabánya), Jossau (Jasov), Telken (Telkibánya), Rossenau (Rožňava) und Neundorf (Spišská / Nová Ves). Die Bergmeister bestätigten die von den Räten beschlossene Satzung und ließen diese in fünf Artikeln im Göllnitzer Stadtbuch eintragen. Die Entstehungszeit fünf weiterer Artikel lässt sich nicht genau bestimmen. In ihnen wurden die Rechte und Pflichten der Bergmeister beschrieben.
    Beschreibung: source
    Schlagwort(e): Slowakei ; Kaschau/Košice ; Zips/Spiš ; Göllnitz/Gelnica ; Schmöllnitz/Smolník ; Ruda/Rudabánya ; Jossau/Jasov ; Telken/Telkibánya ; Rossenau/Rožňava ; Neundorf/(Spišská) Nová Ves ; Silberbergbau ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 8
    Standort Signatur Erwartet Verfügbarkeit
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  • 171
    Publikationsdatum: 2023-02-26
    Beschreibung: Am 24. April 1503 erließ Herzog Georg von Sachsen eine neue Bergordnung für die Bergwerke in Altenberg und Geising. In der Einleitung begründete er den Erlass der neuen Bergordnung damit, dass vor allem die Hutleute, Mühlmeister, Schmelzer und Steiger sich nicht an die 1491 erlassene Ordnung hielten. Die Festlegung der Regeln für den Bergbau in dieser Bergordnung erfolgte in 21 Artikeln. So wurden die Hutleute, Mühlmeister und Schmelzer zum Eid gegenüber dem Bergmeister verpflichtet. Neben der Aufzählung der Plichten der Steiger wurde die Arbeitszeit der Mühlmeister und die Höhe des wöchentlichen Biergeldes für die Schmelzer geregelt. Die Einwohner von Geising und des Geisinggrundes durften nur noch bis abends 9 Uhr Bier und Wein ausschenken. Die Zinnhändler wurden ermahnt, gekauftes Zinn pünktlich zu bezahlen und die festgesetzten Preise einzuhalten.
    Beschreibung: source
    Schlagwort(e): Herzog Georg von Sachsen ; Graupen/Krupka ; Altenberg ; Geising ; Zinnbergbau ; Sachsen ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 7
    Standort Signatur Erwartet Verfügbarkeit
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  • 172
    Publikationsdatum: 2023-01-20
    Beschreibung: Die Entstehung dieser als Bergweistum bezeichnete Bergordnung von Graf Egino IV. für die Bergwerke auf dem Diesselmut am 30. Juni 1372 ist auf die unklaren Rechtsverhältnisse beim Silberbergbau im Breisgau zur damaligen Zeit zurückzuführen. In einem Frage- und Antwortspiel mit 10 namentlich genannten Bergverständigen klärte Graf Egino IV. seine Rechtsansprüche am Silberbergbau.
    Beschreibung: source
    Schlagwort(e): Graf Egino IV. von Freiburg ; Breisgau ; Freiburg im Breisgau ; Kloster St. Trudpert ; Todtnau ; Silberbergbau ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 6
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  • 173
    Publikationsdatum: 2023-01-29
    Beschreibung: Nach dem Erwerb des Geising- und Altenberges durch Herzog Georg von Sachsen erlies er am 25. Juli 1491 eine Ordnung für die dortigen Bergwerke. In den 24 Abschnitten dieser Ordnung wurden neben der Entlohnung die Arbeitszeit, die exakte Abrechnung der geleisteten Arbeit, die Vermessung der Gruben und die Gedingearbeit geregelt. Weiterhin wurde der Betrieb sowie die Finanzierung des Stollens und des Hauptschachtes festgelegt. Geregelt wurden auch der Holzeinschlag für den Bergbau sowie die Verhaltensregeln für die Einwohner der Siedlung bei der Beseitigung von Unrat, dem Umgang mit offenem Feuer, aber auch die Öffnungszeiten der Schankhäuser.
    Beschreibung: source
    Schlagwort(e): Herzog Georg von Sachsen ; Herzog Albrecht von Sachsen ; Graupen/Krupka ; Altenberg ; Geising ; Zinnbergbau ; Sachsen ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 14
    Standort Signatur Erwartet Verfügbarkeit
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  • 174
    Publikationsdatum: 2023-04-06
    Beschreibung: We present first data examples and an estimation of the magnitude of completeness for two BlueSeis-3A rotational seismometers deployed in the West-Bohemia/Vogtland region. The sensors show a surprisingly good sensitivity even for low magnitude events. In seven months, the "Seismologie-Verbund zur Erdbebenbeobachtung in Mitteldeutschland" reported 521 events occurring within a distance of up to 30 km. Based on the signal-noise-ratio, we estimate a magnitude of completeness around a local magnitude of 0.3 for the rotational sensors compared to the completeness of the catalog of -0.7. Moreover, we found that the transversal translation corresponds well to the vertical rotational component for a phase velocity of 2000 m/s and frequencies of 10 to 20 Hz. The data are intended to complement waveform inversions for seismic moment tensors. The study area is characterized by recurring seismic swarms, which are presumably driven by the migration of mantle fluids through the crust. In order to better understand the role of fluids in the earthquake mechanim a good resolution of the non-double-couple (i.e. volumetric and tensile) components of the seismic moment tensor is needed. In that regard, adding rotational data to the inversion has been shown beneficial in synthetic studies. The acquired data will present one of the first examples using field data to invert waveforms for the full seismic moment tensor.
    Beschreibung: poster
    Schlagwort(e): rotational seismology ; BlueSeis ; Vogtland/West-Bohemia
    Sprache: Englisch
    Materialart: doc-type:conferenceObject
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  • 175
    Publikationsdatum: 2023-04-07
    Beschreibung: Dieser Entwurf einer neuen Bergordnung für Glashütte von Herzog Georg von Sachsen wurde am 7. Mai 1491 in Glashütte vorgestellt. Es war eine Erweiterung der am 22. Dezember 1490 erlassenen Bergordnung. Wichtigster Punkt war hier die Verpflichtung, alle aufgenommenen Fundgruben, Maaßen und Schürfe bis zum 24. Juni 1491 besichtigen zu lassen, da diese sonst ins Freie fallen würden. Zur Besichtigung wurden die Bergmeister von Freiberg und Glashütte verpflichtet, die vor Ort entscheiden sollten, ob eine Grube weiter betrieben oder geschlossen wird.
    Beschreibung: source
    Schlagwort(e): Herzog Georg von Sachsen ; Glashütte ; Dippoldiswalde ; Silberbergbau ; Sachsen ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 6
    Standort Signatur Erwartet Verfügbarkeit
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  • 176
    Publikationsdatum: 2023-03-16
    Beschreibung: Diese erste „Große Bergordnung“ für den Zinnbergbau in Altenberg wurde am 1. Mai 1568 von Kurfürst August von Sachsen erlassen. In den insgesamt 49 Paragrafen der Bergordnung wurden der gesamte Bergwerksbetrieb, die Arbeit der Schmelzhütten und Erzmühlen in Altenberg geregelt. Im Gegensatz zu der bisherigen Hierarchie stand jetzt ein vom Landesherren eingesetzter Amtsverwalter über dem Bergmeister. Als oberste Aufsichtsperson wurde zusätzlich ein „Ober-Berg-Meister“ genannt, welcher wiederum dem Amtsverwalter weisungsbefugt war. Diese Hierarchie könnte als Anfang des späteren Oberbergamtes und der damit verbunden Position des Oberberghauptmannes interpretiert werden. In 11 Paragrafen wurde darauf verwiesen, dass die Handlungen analog der Silberbergordnung erfolgen sollten. Hier war wahrscheinlich die Bergordnung von Kurfürst August aus dem Jahr 1554 gemeint, der ersten für das gesamte Kurfürstentum Sachsen gültigen Bergordnung. Am Ende dieser Bergordnung folgten die Eide der Bergbeamten
    Beschreibung: source
    Schlagwort(e): Kurfürst August von Sachsen ; Altenberg ; Zinnbergbau ; Silberbergbau ; Sachsen ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 30
    Standort Signatur Erwartet Verfügbarkeit
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  • 177
    facet.materialart.
    Unbekannt
    Publikationsdatum: 2023-04-17
    Beschreibung: Diese Bergordnung für Kremnitz (Kremnica) wurde am 26. November 1492 auf Initiative des Oberkammergrafen Peter Schaider (hoher Beamter im Königreich Ungarn) sowie des königlichen Bergmeisters und Steigers Niclas Czor in das Stadtbuch von Kremnitz eingetragen. Hintergrund dafür waren wahrscheinlich zunehmende Probleme bei der Einhaltung der gültigen Rechtsnormen des Bergbaus. Beschrieben wurden die Aufnahme von Fundgruben sowie deren Rechte, die Maße des Grubenfeldes die Anforderungen an Schächte und Schürfe und die technische Ausstattung eines Göpels. Bei allen genannten Punkten wurde immer wieder auf altes Recht und Gewohnheit verwiesen.
    Beschreibung: source
    Schlagwort(e): Slowakei ; Ungarn ; Kremnitz/Kremnica ; Iglau/Jihlava ; Freiberg ; Silberbergbau ; Bergordnung
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 15
    Standort Signatur Erwartet Verfügbarkeit
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  • 178
    Publikationsdatum: 2023-03-24
    Beschreibung: The AdriaArray project addresses fundamental questions related to the geodynamics and the deformation and stress field of the Adriatic plate in south-eastern Europe. The observational basis of AdriaArray is a recently formed seismic broadband array that joins newly deployed temporary and existing permanent stations all over the entire Adriatic plate. Here, we report on the deployment of temporary stations by Ruhr-University Bochum (RUB) in Greece and Northern Macedonia. This contribution enhances the local networks by 35 new temporary stations and upgrades the instruments at 17 permanent sites. Most of these sites are equipped with broadband instruments from the German DSEBRA array which were previously installed within the scope of the AlpArray project. Deployment started with 37 stations in Greece at the end of September / beginning of October 2022 in cooperation with partners from the universities of Thessaloniki, Athens and Patras, as well the National Observatory of Athens (NOA). The deployment of stations in North Macedonia is planned for February 2023 in cooperation with the Seismological Observatory of the University of Skopje. All stations are supplied with mobile routers for live-streaming of waveform data and for monitoring the state-of-health of the stations. Data is streamed in near real-time to servers of the Seismological Observatory of the RUB and to the EIDA node of NOA. The FDSN network code 1Y is assigned to the temporary stations, while the upgraded permanent stations remain a part of their original networks. The newly deployed stations in Greece were able to register data of the still ongoing seismic series of Evia which started in November 2022. We present examples of the recorded seismograms from these events and estimate the quality of the stations by calculating probability power spectral densities (PPSD) to ensure that the stations meet the quality requirements of the AdriaArray project. First results of the calculated PPSDs illustrate the overall performance of these stations and help to identify problematic stations for which alternative sites have to be scouted.
    Beschreibung: poster
    Sprache: Englisch
    Materialart: doc-type:conferenceObject
    Standort Signatur Erwartet Verfügbarkeit
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  • 179
    facet.materialart.
    Unbekannt
    ARGE GMIT, Bonn
    In:  ARGE GMIT
    Publikationsdatum: 2023-03-27
    Beschreibung: Die Ausgabe der Geowissenschaftlichen Mitteilungen vom September 2022 enthält die Themenblöcke: GEOfokus: Zwischen Scylla und Charybdis - Die Rolle von Recycling und Primärrohstoffen am Beispiel von Kupfer und Lithium, GEOaktiv (Wirtschaft, Beruf, Forschung und Lehre), GEOlobby (Gesellschaften, Verbände, Institutionen), GEOreport (Geowissenschaftliche Öffentlichkeitsarbeit, Tagungsberichte, Ausstellungen, Exkursionen, Publikationen), GEOszene (Würdigungen, Nachrufe).
    Beschreibung: journal
    Schlagwort(e): ddc:550 ; GMIT
    Sprache: Deutsch
    Materialart: doc-type:book , publishedVersion
    Format: 124
    Standort Signatur Erwartet Verfügbarkeit
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  • 180
    facet.materialart.
    Unbekannt
    Publikationsdatum: 2023-04-01
    Beschreibung: Diese Im Stadtbuch von Göllnitz (Gelnica) unter dem Jahr 1498 eingetragene Stollenordnung für Göllnitz geht auf eine ältere Stollenordnung zurück. Sie wurde anlässlich einer am 5. Oktober 1498 auf Antrag des Kanzlers des Königreiches Ungarn, dem Erzbischof von Gran (Esztergom), Tamás Bakócz (Thomas) in Göllnitz, stattfindenden Verhandlung in das Stadtbuch eingetragen. In dieser Verhandlung ging es um die Klärung eines Rechtsstreites zum Stollenrecht, der Verleihung von Fundgruben samt Stollen sowie der Vermessung der Gruben und Maaßen. Der Rechtsstreit war zwischen Gewerken aus Rosenau (Rožňava) und dem Rat der Bergstadt Rosenau entflammt.
    Beschreibung: source
    Schlagwort(e): Ungarn ; Slowakei ; Göllnitz/Gelnica ; Zips/Spiš ; Schemnitz/Baňská Štiavnica ; Kremnitz/Kremnica ; Rosenau/Rožňava ; Gran/Esztergom ; Iglau/Jihlava ; Tamás Bakócz (Erzbischof) ; Stephan Zápolya (Oberkammergraf) ; Stollenordnung ; Silberbergbau
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
    Format: 6
    Standort Signatur Erwartet Verfügbarkeit
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  • 181
    Publikationsdatum: 2023-04-03
    Beschreibung: Digitale Gelände-Modelle (DGM) erstellt aus Laserscan-Daten und Daten der Persistent Scatterer Interferometrie (PSI) bieten Datengrundlagen zur Analyse von großflächigen Bodenbewegungen im cm- und mm-Bereich. Es besteht ein Bedarf an geeigneten Verarbeitungs- und Interpretationswerkzeugen für diese Datenquellen, um sie der breiten Öffentlichkeit zur Nutzung zur Verfügung zu stellen. Die dafür notwendigen Arbeiten werden innerhalb des Umwelt 4.0 – Projektes, Cluster I – „Nutzung digitaler Geländemodelle und Copernicus-Daten“, durchgeführt, welches vom Hessischen Landesamt für Naturschutz, Umwelt und Geologie in Kooperation mit der TU Darmstadt durchgeführt und von der Hessischen Ministerin für Digitale Strategie und Entwicklung gefördert wird. Um automatisch Bewegungs-Hot-Spots in Hessen zu detektieren, werden mittels eines erstellten GIS-Tools Gebiete, die detektierbare Setzungen (Geschwindigkeit 〈 - 2 mm/a) oder Hebungen (Geschwindigkeit 〉 2 mm/a) aufweisen und in denen möglichst viele Persistent Scatterer Bewegungsgeschwindigkeiten aufweisen, ermittelt. Je stärker eine Bodenbewegung ist und je mehr Persistent Scatterer diese Bodenbewegung anzeigen, desto stärker wird dieser Bereich hervorgehoben. Zur Analyse der Bewegungsursachen werden die Zeitreihen mittels Fitting untersucht und des Weiteren mit möglichen Bewegungsursachen der Region verglichen. Um die räumlichen Lücken der Persistent Scatterer Daten in unbebauten Regionen zu füllen, wird an zwei unterschiedlichen Lösungen gearbeitet. Zum einen werden Differenzenkarten aus Digitalen Geländemodellen, die zu unterschiedlichen Zeitpunkten aufgenommen wurden, erstellt. Zum anderen soll das Small Baseline Subset (SBAS)-Verfahren Anwendung finden. Der hier beschriebene Workflow liefert verschiedene Bewegungs-Hot-Spots in Hessen. Anhand von Fallbeispielen werden erste Ergebnisse des Projektes vorgestellt. Die räumliche Fusion der PSI-Daten mit Differenzenkarten und SBAS-Daten ist im weiteren Projektverlauf vorgesehen.
    Beschreibung: Hessische Ministerin für Digitale Strategie und Entwicklung
    Beschreibung: poster
    Schlagwort(e): Fernerkundung ; Sentinel-1 ; Radarinterferometrie ; Laserscan ; Bodenbewegung ; Hessen
    Sprache: Deutsch
    Materialart: doc-type:conferenceObject
    Standort Signatur Erwartet Verfügbarkeit
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  • 182
    Publikationsdatum: 2023-04-19
    Beschreibung: Induced seismicity during mine flooding is the focus of the FloodRisk project. One of the study areas is the Ruhr area, which is characterised by centuries of intensive coal mining. After the closure of the last mines, controlled flooding began. Within the FloodRisk project, we investigate ground uplift, stress changes due to pore pressure changes and the reactivation potential of faults to explain induced seismicity. We concentrate on the seismicity monitoring and geomechanics of the Haus Aden catchment, for which we investigate the relationship between water rise, tectonic stress and induced seismicity. The monitoring of seismicity is based on a network of up to 30 short-period seismic stations installed by the Ruhr University in the area of the former "Bergwerk Ost", which exhibited the highest seismicity in the Ruhr area during active mining. The stations cover an area of about 160 km 2 and are spaced between 0.5 and 3.5 km apart. They allow continuous monitoring of seismicity. Since 2019, more than 2200 induced events have been localised. A prerequisite for the interpretation of seismicity is a detailed localisation of the events. The relative localisation of the induced earthquakes has significantly reduced the location uncertainty and allowed the spatial and temporal evolution of earthquake clusters due to the rise in mine water levels to be studied. The resulting pattern of seismicity was compared with known underground structures. This comparison indicates that most of the events occur approximately 300 m below the main pillars between the longwall panels in the already flooded deepest level of the mine. A generic FE numerical model was developed for a section of the Heinrich Robert mine based on the geometry of the pillars, shafts and longwall panels. The stress data for model calibration are based on a compilation of the regional stress state in the eastern Ruhr area. For this purpose, hydraulic fracture tests carried out in the mines to minimise rock bursts were re-evaluated and compared with stress orientations derived from independent sources such as borehole fractures and earthquake source mechanisms. Using this 3D numerical approach, we conclude that there is increased vertical stress within and below the pillars as a result of stress arching. As the horizontal stress changes below the mine levels are small, this results in increasing differential stresses that can lead to the observed events below the mine level when the mine water level rises.
    Beschreibung: Bundesministerium für Bildung und Forschung
    Beschreibung: poster
    Schlagwort(e): induced seismicity ; post mining ; mine water rise ; numerical stress model ; stress arching ; failure potential
    Sprache: Englisch
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  • 183
    facet.materialart.
    Unbekannt
    Publikationsdatum: 2023-04-22
    Beschreibung: Dieser als Freiberger Bergrecht B oder Jüngeres Freiberger Bergrecht bezeichneter Gesetzestext, ist wahrscheinlich nach der Chemnitzer Teilung vom 13. November 1382 entstanden. In 43 Paragrafen wurde das zu dieser Zeit gültige Bergrecht niedergeschrieben. Das Bergrecht ist eine Mischung aus dem Freiberger Bergrecht A und der deutschen Version des Iglauer Bergrechtes. Die Entstehungszeit der verwendeten Variante des Iglauer Bergrechtes ist allerdings unbekannt.
    Beschreibung: source
    Schlagwort(e): Wilhelm I. Markgraf von Meißen ; Balthasar Landgraf von Thüringen ; Friedrich I. Herzog von Sachsen ; Wilhelm II. Herzog von Sachsen ; Georg Herzog von Sachsen ; Freiberg ; Iglau/Jihlava ; Silberbergbau ; Bergrecht
    Sprache: Deutsch
    Materialart: doc-type:book , updatedVersion
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  • 184
    Publikationsdatum: 2023-06-20
    Beschreibung: Thin sections of three Palaeozoic bryozoans reveal fossilized soft tissues that show the position of organic cuticle and internal structures such as the membranous sac and gut. The fossilization occurred apparently due to fast burial under anoxic conditions. The position of a membranous sac in the Permian trepostome Rhombotrypella superangustata is indicative of a progressive polypide cycle. The position of the polypide in the Ordovician Graptodictya delicata behind the superior and interior hemisepta suggests a protective function of the hemisepta.
    Schlagwort(e): ddc:564 ; morphology ; Bryozoa ; fossilization ; Palaeozoic
    Sprache: Englisch
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  • 185
    Publikationsdatum: 2023-06-20
    Beschreibung: Whether Archean tectonics were horizontally or vertically dominated is controversially discussed because arguments bear on the kinematics and thermal state of the Archean mantle and constrain the mode of formation of the earliest continental crust. Highly deformed strata of Archean greenstone belts figure prominently in this debate because they record long periods of time and multiple deformation phases. Among the best‐preserved greenstone belts counts the Barberton Greenstone Belt (BGB) of southern Africa. Geological mapping of part of the southern BGB in Eswatini (Swaziland), combined with U‐Pb zircon dating, shows that the region preserves a tightly re‐folded imbricate thrust stack in which metavolcanic and ‐volcaniclastic strata of the Onverwacht Group, deposited at 3.34–3.29 Ga, have been thrust on top of ca. 3.22 Ga siliciclastic strata of the Moodies Group. The structurally highest element, the Malolotsha Syncline, forms a tectonic klippe of substantial size and is 〉1,450 m thick. Forward modeling of a balanced cross section indicates that this thrust stack was part of a northwestward‐verging orogen along the southern margin of the BGB and records a minimum horizontal displacement of 33 km perpendicular to its present‐day faulted, ductily strained and multiply metamorphosed margin. Because conglomerate clasts indicate a significantly higher degree of prolate strain which extends further into the BGB than at its northern margin, late‐stage tectonic architecture of the BGB may be highly asymmetrical. Our study documents that the BGB, and perhaps other Archean greenstone belts, preserves a complex array of both vertically‐ and horizontally‐dominated deformation styles that have interfered with each other at small regional and short temporal scales.
    Beschreibung: Plain Language Summary: Worldwide, only a few regions exist where ancient rock strata document how earth cooled, surface strata deformed, and continents grew. It is debated whether vertical movements dominated (akin to a lava lamp) and when major horizontal motions (as they dominate Earth today) began; certainly, there was also overlap between these regimes. Radiometric age dating of zircons extracted from strata along the southern margin of one of the best‐preserved ancient regions in southern Africa, the Barberton Greenstone Belt in Eswatini, show that older strata were thrust there over younger strata for at least 33 km distance subhorizontally. Then they were shingled, and then folded. The results show that even at a time when Earth's oldest continents were just forming, significant horizontal displacements existed already.
    Beschreibung: Key Points: U‐Pb zircon dating and geological mapping confirm a folded thrust‐stack along part of the southern margin of the Archean Barberton Greenstone Belt (BGB). Forward modeling of a balanced cross‐section indicates 〉33 km of horizontal shortening toward the northwest. Vertically‐ and horizontally‐dominated tectonics interfered with each other in the BGB and may have done so in other Archean greenstone belts as well.
    Beschreibung: Friedrich‐Schiller‐University Jena
    Beschreibung: https://doi.org/10.5880/fidgeo.2022.037
    Schlagwort(e): ddc:551.8 ; Greenstone Belt ; Archean ; Eswatini ; Klippe ; Barberton ; Swaziland
    Sprache: Englisch
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  • 186
    Publikationsdatum: 2023-06-16
    Beschreibung: The angular momentum of the Earth‐Moon system was initially dominated by Earth's rotation with a short solar day of around 5 hr duration. Since then, Earth gradually transferred angular momentum through tidal friction to the orbit of the Moon, resulting in an increasing orbital radius and a deceleration of Earth's rotation. Geologic observations of tidal deposits can be used to verify and constrain models of lunar orbital evolution. In this work we reexamine the oldest tidal record suitable for analysis from the Moodies Group, South Africa, with an age of 3.22 billion years. Time frequency analysis of the series of thicknesses of the sandstone‐shale layers yields a periodicity of 15.0 layers, taking into account the possibility of missing laminae. Assuming a mixed tidal system, the duration of two neap‐spring‐neap cycles was 30.0 lunar days for dominant semidiurnal or 30.0 sidereal days for dominant diurnal tides. We derive the relationship between this observation and the past Earth‐Moon distance and re‐visit related published work. We find that the Earth‐Moon distance 3.2 billion years ago was about 70% of today's value. The Archean solar day was around 13 hr long. The ratio of solar to lunar tide‐raising torque controls the leakage of angular momentum from the Earth‐Moon system, but deviation from the assumed ratio of 0.211 results in only moderate changes. A duration of a postulated 21‐hr atmospheric resonance shorter than 200 million years would be consistent with our observation; it would significantly alter the Earth‐Moon distance.
    Beschreibung: Plain Language Summary: After its formation 4.5 billion years ago, the Moon circled Earth in a low orbit while Earth rotated faster than today around its axis. In the course of time, the Moon gradually evolved to a higher orbit while the rotation of Earth slowed due to the frictional effect of tides. Theoretical models can describe the evolution of the distance between Earth and the Moon with time until today. Counting the thickness of thin sandstone‐shale couplets of known age, which are layered due to tides, can constrain these models. In this work we reexamine the oldest of these geological records in the Moodies Group of South Africa, with an age of 3.2 billion years. The thickness of layers changes with a periodicity of 15 layers which is assumed to originate from varying strengths of currents between successive spring tides. Kepler's third law and the law of conservation of angular momentum allow us to derive the parameters of the lunar orbit from this measurement. According to our analysis, the Earth‐Moon distance was around 70% of today's value 3.2 billion years ago. The faster rotation rate of Earth resulted in a length of day of around 13 hr.
    Beschreibung: Key Points: Time frequency analysis yields 30.0 layers per two neap‐spring‐neap cycles, taking missing laminae in the tidal record into account. Earth‐Moon distance of ca. 70% of today's value 3.2 billion years ago results in a solar day of 13 hr duration. Duration of 21‐hr atmospheric resonance for 〈200 million years is consistent with our observation, alters estimate of Earth‐Moon distance.
    Schlagwort(e): ddc:523 ; Earth‐Moon system ; lunar orbital evolution ; tidal friction ; Moodies Group ; tidal deposits ; time‐frequency analysis
    Sprache: Englisch
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  • 187
    Publikationsdatum: 2023-06-12
    Beschreibung: Soils and landscapes are bridges of space and time, as they simultaneously and authentically show essential aspects that were previously separated by time and space (such as cultural and activity-related aspects from past and present) to the trained observer - albeit only in excerpts. Therefore, this article presents a series of impact indicators for soil changes, starting with extreme (anthropogenic) interventions and ending with equally extreme ("natural") events. An essential difference to specifically planning-relevant or human ecological concepts, which, for example, specify land use/load categories, is that the following impact indicators perceive soils as a phenomenon in themselves and do not define them through attributed functions. Particular attention is focused on their changeability and vital development potential, as well as on their property as a sphere of penetration of living and material things, with emphasis on the noetic effect. The intervention or event spaces on the earth's surface can be differentiated quantitatively through the type, strength, and duration of the phenomena. The intensity of all processes can be described by amplitude (the strength of the interventions/events) and frequency (the repetition rate of the interventions/events) and can be specifically identified and quantified by, for example, material inputs or outputs per unit of time. For the first time, there would be a system for measuring the ecological quality of anthropogenic land use, which could serve as an "alert system for the external technological culture," and could help us become aware of our "inner" culture.
    Beschreibung: research
    Schlagwort(e): ddc:550 ; Boden ; Landschaft ; Bodendegeneration ; Deutschland ; Anthropogene Bodenveränderung
    Sprache: Deutsch
    Materialart: doc-type:article
    Format: 9
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  • 188
    Publikationsdatum: 2023-06-19
    Beschreibung: Geochemical analyses of carbonate minerals yield multiple parameters which can be used to estimate the temperature and water composition at which they formed. Analysis of fluid trapped in minerals is a potentially powerful tool to reconstruct paleotemperatures as well as diagenetic and hydrothermal processes, as these could represent the parent fluid. Internal fluids play important roles during the alteration of carbonate fossils, lowering energetic barriers associated with resetting of clumped isotopes, as well as mediating the transport of elements during diagenesis. Here, we explore the behavior of the ∆47–∆48 “dual‐clumped” isotope thermometer during fluid‐carbonate interaction and demonstrate that it is highly sensitive to the water/carbonate ratio, behaving as a linear system in “rock buffered” alteration, and as a decoupled system in water‐dominated systems due to non‐linear mixing effects in ∆48. Dry heating experiments show that the extrapolated “heated” end‐member is indistinguishable from the predicted ∆47 and ∆48 value expected for the experimental temperature. Furthermore, we evaluate two common laboratory sampling methods for their ability to thermally alter samples. We find that the temperature of the commonly used crushing cells used to vapourize water for fluid inclusion δ18O analyses is insufficient to cause fluid‐carbonate oxygen isotope exchange, demonstrating its suitability for analyses of fluid inclusions in carbonates. We also find that belemnites sampled with a hand‐drill yield significantly warmer paleotemperatures than those sampled with mortar and pestle. We conclude that thermally‐driven internal fluid‐carbonate exchange occurs indistinguishably from isotopic equilibrium, limited by the extent to which internal water and carbonate can react.
    Beschreibung: Plain Language Summary: Carbonate minerals contain multiple, independent, chemical and isotopic parameters which can be used to calculate the temperature at which the mineral formed. If these proxies agree with one another, it has been confidently assumed that the temperature is indeed genuine. Here, we investigate three such parameters and show how they record kinetic processes during mineral formation, as well as thermally‐driven processes which may alter a climate record. We find that this method could potentially be used to study the kinetic factors at play during biomineralization, even if the “true” temperature is unknown. We also find that some thermal processes result in all three parameters agreeing with one another. Because thermal alteration poses a potential dilemma for climate researchers, we investigate two common laboratory preparation techniques that involve heating a sample before analysis: drilling and heating sample for fluid inclusion analysis. We find that the heat of a drill is sufficient to facilitate these reactions, and potentially imparts a warm bias onto paleotemperatures, however the apparatus used for analyzing fluid inclusions does not appear to significantly alter the material. We conclude our approach using fluid inclusion analysis and dual‐clumped isotopes has the potential to resolve many ambiguities in interpreting climate records.
    Beschreibung: Key Points: We explore the behavior of dual‐clumped and fluid‐inclusion isotope paleothermometers during thermal alteration. Different conditions during diagenesis may result in discrepant paleotemperature estimates, which may be used to identify altered records. Hand‐drilling belemnites produces sufficient heat to reset paleotemperatures, but the heat during analysis of fluid inclusions does not.
    Beschreibung: DFG
    Beschreibung: https://doi.org/10.5281/zenodo.7565557
    Schlagwort(e): ddc:551.9 ; diagenesis ; clumped isotopes ; fluid inclusions ; numerical modeling
    Sprache: Englisch
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  • 189
    Publikationsdatum: 2023-06-19
    Beschreibung: Energetic particle acceleration and energization in planetary magnetotails are often associated with dipolarization fronts characterized by a rapid increase of the meridional component of the magnetic field. Despite many studies of dipolarization events in Earth's magnetotail, Jupiter’s magnetotail provides an almost ideal environment to study high‐energetic ion acceleration by dipolarization fronts because of its large spatial scales and plasma composition of heavy and light ions. In this study, we focus on the response of different high‐energetic ion intensities (H, He, S, and O) to prominent magnetic dipolarization fronts inside the Jovian magnetotail. We investigate if ion energization and acceleration are present in the observations around the identified dipolarization fronts. Therefore, we present a statistical study of 87 dipolarization front signatures, which are identified in the magnetometer data of the Juno spacecraft from July 2016 to July 2021. For the ion intensity analysis, we use the energetic particle observations from the Jupiter Energetic Particle Detector Instrument. Our statistical study reveals that less than half of the identified events are accompanied by an increase of the ion intensities, while most of the other events show no significant change in the ion intensity dynamics. In about 40% of the events located in the dawn sector a significant decrease of the energy spectral index is detected indicating ion acceleration by the dipolarization fronts.
    Beschreibung: Key Points: Eighty‐seven prominent dipolarization front signatures are observed in the MAG data during Juno's prime mission during 21:00–05:30 local time. Less than half of the identified events are accompanied by an increase of the ion intensities. In 40% of the events observed on the dawn side a significant decrease of the energy spectral index indicates ion acceleration by the fronts.
    Beschreibung: Volkswagen Foundation http://dx.doi.org/10.13039/501100001663
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: https://doi.org/10.17189/1519711
    Beschreibung: https://doi.org/10.17189/1519713
    Schlagwort(e): ddc:523 ; Juno ; Jovian magnetotail ; energetic ions ; dipolarization fronts ; JEDI
    Sprache: Englisch
    Materialart: doc-type:article
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  • 190
    Publikationsdatum: 2023-07-18
    Beschreibung: Methane seeps are typified by the formation of authigenic carbonates, many of which exhibit corrosion surfaces and secondary porosity believed to be caused by microbial carbonate dissolution. Aerobic methane oxidation and sulfur oxidation are two processes capable of inducing carbonate corrosion at methane seeps. Although the potential of aerobic methanotrophy to dissolve carbonate was confirmed in laboratory experiments, this process has not been studied in the environment to date. Here, we report on a carbonate corrosion experiment carried out in the REGAB Pockmark, Gabon‐Congo‐Angola passive margin, in which marble cubes were deployed for 2.5 years at two sites (CAB‐B and CAB‐C) with apparent active methane seepage and one site (CAB‐D) without methane seepage. Marble cubes exposed to active seepage (experiment CAB‐C) were found to be affected by a new type of microbioerosion. Based on 16〈italic toggle="no"〉S r〈/italic〉RNA gene analysis, the biofilms adhering to the bioeroded marble mostly consisted of aerobic methanotrophic bacteria, predominantly belonging to the uncultured Hyd24‐01 clade. The presence of abundant 〈sup〉13〈/sup〉C‐depleted lipid biomarkers including fatty acids (〈italic toggle="no"〉n〈/italic〉‐C〈sub〉16:1ω8c〈/sub〉, 〈italic toggle="no"〉n〈/italic〉‐C〈sub〉18:1ω8c〈/sub〉, 〈italic toggle="no"〉n〈/italic〉‐C〈sub〉16:1ω5t〈/sub〉), various 4‐mono‐ and 4,4‐dimethyl sterols, and diplopterol agrees with the dominance of aerobic methanotrophs in the CAB‐C biofilms. Among the lipids of aerobic methanotrophs, the uncommon 4α‐methylcholest‐8(14)‐en‐3β,25‐diol is interpreted to be a specific biomarker for the Hyd24‐01 clade. The combination of textural, genetic, and organic geochemical evidence suggests that aerobic methanotrophs are the main drivers of carbonate dissolution observed in the CAB‐C experiment at the REGAB pockmark.〈/p〉
    Beschreibung: Deutscher Akademischer Austauschdienst http://dx.doi.org/10.13039/501100001655
    Schlagwort(e): ddc:550 ; carbonate ; corrosion ; lipid biomarker ; methane seep ; methanotrophic bacteria ; microbioerosion
    Sprache: Englisch
    Materialart: doc-type:article
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  • 191
    Publikationsdatum: 2023-07-19
    Beschreibung: The derivation of a crystal structure and its phase‐specific parameters from a single wide‐angle backscattered Kikuchi diffraction pattern requires reliable extraction of the Bragg angles. By means of the first derivative of the lattice profile, an attempt is made to determine fully automatically and reproducibly the band widths in simulated Kikuchi patterns. Even under such ideal conditions (projection centre, wavelength and lattice plane traces are perfectly known), this leads to a lattice parameter distribution whose mean shows a linear offset that correlates with the mean atomic number Z of the pattern‐forming phase. The consideration of as many Kikuchi bands as possible reduces the errors that typically occur if only a single band is analysed. On the other hand, the width of the resulting distribution is such that higher image resolution of diffraction patterns, employing longer wavelengths to produce wider bands or the use of higher interference orders is less advantageous than commonly assumed.
    Beschreibung: The lattice parameters of more than 350 phases have been determined from simulated backscatter Kikuchi patterns. The deviations correlating with the mean atomic number correspond to those observed previously for experimental electron backscatter diffraction patterns.
    Schlagwort(e): ddc:548 ; Bragg angles ; Kikuchi bands ; Kikuchi patterns ; first derivative ; lattice parameters ; lattice parameter determination ; Bravais lattice type ; electron backscatter diffraction ; Radon transform
    Sprache: Englisch
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  • 192
    Publikationsdatum: 2023-07-19
    Beschreibung: Serial crystallography experiments produce massive amounts of experimental data. Yet in spite of these large‐scale data sets, only a small percentage of the data are useful for downstream analysis. Thus, it is essential to differentiate reliably between acceptable data (hits) and unacceptable data (misses). To this end, a novel pipeline is proposed to categorize the data, which extracts features from the images, summarizes these features with the `bag of visual words' method and then classifies the images using machine learning. In addition, a novel study of various feature extractors and machine learning classifiers is presented, with the aim of finding the best feature extractor and machine learning classifier for serial crystallography data. The study reveals that the oriented FAST and rotated BRIEF (ORB) feature extractor with a multilayer perceptron classifier gives the best results. Finally, the ORB feature extractor with multilayer perceptron is evaluated on various data sets including both synthetic and experimental data, demonstrating superior performance compared with other feature extractors and classifiers.
    Beschreibung: A machine learning method for distinguishing good and bad images in serial crystallography is presented. To reduce the computational cost, this uses the oriented FAST and rotated BRIEF feature extraction method from computer vision to detect image features, followed by a multilayer perceptron (neural network) to classify the images.
    Schlagwort(e): ddc:548 ; serial crystallography ; data reduction ; machine learning ; feature extraction
    Sprache: Englisch
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  • 193
    Publikationsdatum: 2023-07-19
    Beschreibung: Large Igneous Provinces (LIPs) are unusual volcanic events in which massive amounts of melt (∼106 km3) erupt in relatively short time periods (〈106 years). Most LIP magmas have undergone extensive fractional crystallization and crustal contamination, but the crustal magmatic plumbing systems and the processes triggering eruptions are poorly understood. We present new major and trace element and radiogenic isotope data for 43 individual lava flows from a continuous 1,200 m thick stratigraphic profile through the upper, most voluminous part of the Deccan LIP (Bushe to Mahabaleshwar Formations). Eruption rates for this section are constrained by published paleomagnetic directions and absolute U‐Pb ages for zircons from weathered flow tops exposed in the profile. We find four magmatic sequences each lasting ∼104–∼105 years during which major and trace element compositions change systematically, followed by an abrupt change in geochemistry at the start of a new sequence. Within each sequence, the MgO content and proportion of crustal contamination decrease progressively, indicating a continuous replenishment of the associated magma reservoirs with less contaminated but more evolved melts. These geochemical signatures are best explained by repeated episodes of melt recharge, mixing, and eruption of variably evolved magmas originating from relatively small magma reservoir located in different crustal levels.
    Beschreibung: Plain Language Summary: Volcanism occurs predominantly at plate boundaries, either at mid‐ocean ridges or subduction zones, where most mantle melts are produced. However, the Earth's history is punctuated by volcanic events which are not related to plate boundary processes and during which large amounts of melt erupt (∼106 km3) in relatively short periods of time (〈106 years). These Large Igneous Provinces (LIPs) are associated with the activity of mantle plumes and eruption rates during their main stages are significantly higher than those of today's largest magmatic systems. However, since no LIP is currently active, the architecture of the associated plumbing systems is relatively unknown. In order to understand the magmatic processes during the emplacement of a LIP, we generated geochemical data from a continuous stratigraphic profile covering the most voluminous stage of the ∼66 Ma Deccan LIP. By combining these new data with published paleomagnetic directions and absolute U‐Pb ages for zircons, we found four eruption sequences each lasting ∼104–∼105 years. During these sequences, geochemical compositions change systematically, which is best explained by repeated episodes of melt recharge, mixing, and eruption of variably evolved magmas originating from relatively small magma reservoirs located at different crustal levels.
    Beschreibung: Key Points: Four recharge‐crystallization‐eruption sequences fed the most voluminous Deccan lava. Magmatic plumbing system with interconnected small‐ to medium‐sized magma reservoirs. Complex emplacement history including multiple stages of ascent, mixing, and storage.
    Beschreibung: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659
    Beschreibung: https://doi.org/10.26022/IEDA/112672
    Schlagwort(e): ddc:551.9 ; intraplate processes ; magma chamber processes ; magma genesis and partial melting ; major and trace element geochemistry ; radiogenic isotope geochemistry
    Sprache: Englisch
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  • 194
    Publikationsdatum: 2023-07-19
    Beschreibung: Limited constraints on the variability of the deep‐water production in the Labrador Sea complicate reconstructions of the strength of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Quaternary. Large volumes of detrital carbonates were repeatedly deposited in the Labrador Sea during the last 32 kyr, potentially affecting radiogenic Nd isotope signatures. To investigate this the Nd isotope compositions of deep and intermediate waters were extracted from the authigenic Fe‐Mn oxyhydroxide fraction, foraminiferal coatings, the residual silicates and leachates of dolostone grains. We provide a first order estimation of Nd release via dissolution of detrital carbonates and its contribution to the authigenic ԑNd signatures in the Labrador Sea. During the Last Glacial Maximum the Nd isotope signatures in the Labrador Sea would allow active water mass mixing with more radiogenic ɛNd values (−12.6 and −14) prevailing in its eastern part whereas less radiogenic values (ɛNd ∼ −18.4) were found on the western Labrador slope. The deposition of detrital carbonates during Heinrich stadials (2,1) was accompanied by negative detrital and authigenic Nd isotope excursions (ɛNd ∼ −31) that were likely controlled by dissolution of dolostone or dolostone associated mineral inclusions. This highly unradiogenic signal dominated the authigenic phases and individual water masses in the Labrador Sea, serving as potential source of highly unradiogenic Nd to the North Atlantic region, while exported southward. The Holocene authigenic ɛNd signatures of the coatings and leachates significantly differed from those of the detrital silicates, approaching modern bottom water mass signatures during the Late Holocene.
    Beschreibung: Plain Language Summary: The Labrador Sea is an important region for deep water formation and for the ocean circulation in the Atlantic region. Over the last 32 thousand years, numerous discharges from melting glaciers added freshwater to the Labrador Sea which could help understand the future effects of current melting glaciers. This information is necessary to better constrain climate predictions in order to gauge the effects on the Global Ocean Water Circulation. However, past deep water production in the Labrador is still poorly constrained, complicating reconstruction of the Atlantic Meridional Overturning Circulation on different timescales. In this study we investigated changes in deep and intermediate water mass circulation patterns over the last 32 kyr based on the radiogenic Nd isotope compositions that serve as a water mass circulation proxy. Analysis of four marine sediment cores show that the deposition of large volumes of detrital carbonates during studied period had a large effect on the recorded in the sediment column signals. New data suggest active water mass circulation during the maximum extent of glacial ice sheets. The modern day ocean circulation patterns have emerged during the Late Holocene (6 ka).
    Beschreibung: Key Points: Estimation of Nd release via dissolution of detrital carbonates and its contribution to the authigenic ԑNd signatures in the Labrador Sea. Dissolution of detrital dolostones in the water column during Heinrich stadials at least partially controlled ɛNd signatures. During the LGM generally more radiogenic signatures possibly indicate active water mass advection and mixing in the Labrador Sea.
    Beschreibung: GEOMAR Helmholtz‐Zentrum für Ozeanforschung Kiel http://dx.doi.org/10.13039/501100003153
    Beschreibung: Kiel University
    Beschreibung: https://doi.org/10.1594/PANGAEA.952659
    Schlagwort(e): ddc:551.9 ; Labrador Sea ; Late Quaternary ; Paleoceanography ; neodymium isotopes ; dolostone ; AMOC ; carbonate dissolution ; Heinrich stadials
    Sprache: Englisch
    Materialart: doc-type:article
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  • 195
    Publikationsdatum: 2023-07-19
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Whereas it is now widely accepted that cumulus cloud sizes are power‐law distributed, characteristic exponents reported in the literature vary greatly, generally taking values between 1 and >3. Although these differences might be explained by variations in environmental conditions or physical processes organizing the cloud ensembles, the use of improper fitting methods may also introduce large biases. To address this issue, we propose to use a combination of maximum likelihood estimation and goodness‐of‐fit tests to provide more robust power‐law fits while systematically identifying the size range over which these fits are valid. The procedure is applied to cloud size distributions extracted from two idealized high‐resolution simulations displaying different organization characteristics. Overall, power‐laws are found to be outperformed by alternative distributions in almost all situations. When clouds are identified based on a condensed water path threshold, using power‐laws with an exponential cutoff yields the best results as it provides superior fits in the tail of the cloud size distributions. For clouds identified using a combination of water content and updraft velocity thresholds in the free troposphere, no substantial improvement over pure power‐laws can be found when considering more complex two‐parameter distributions. In this context however, exponential distributions provide results that are as good as, if not better than power‐laws. Finally, it is demonstrated that the emergence of scale free behaviors in cloud size distributions is related to exponentially distributed cloud cores merging as they are brought closer to each other by underlying organizing mechanisms.〈/p〉
    Beschreibung: Plain Language Summary: Clouds constitute an important element of the climate system reflecting incoming solar radiation and emitting infra‐red radiation that heats the atmosphere. The net radiative impact of clouds however depends on many factors including their size. It is thus of prime importance to characterize the size of clouds, in particular convective clouds, and understand the underlying processes controlling them. In this study, a numerical model is used to simulate two convective situations at horizontal resolutions providing a fine description of cloud processes. After identifying individual clouds and calculating their size, statistical methods are employed to characterize the cloud size distributions. Depending on the situation, cloud size distributions are found to be best represented by either power‐laws with an exponential cutoff or exponential functions. Pure power‐laws, which constitute the most popular model used to represent cloud size distributions, are generally found to yield poorer fits. Finally, it is demonstrated that power‐laws in cloud size distributions emerge when individual cloud cores, that are exponentially distributed in size, are brought closer to each other and merge as the cloud ensemble organizes.〈/p〉
    Beschreibung: Key Points: A combination of statistical methods is used to fit cloud size distributions from two simulated convective cloud ensembles.〈/p〉〈/list-item〉 〈list-item〉〈p〉Depending on the situation, exponential distributions and power‐laws with an exponential cutoff may constitute superior alternatives to pure power‐laws.〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉The merging of individual cloud cores is found to control the emergence of power‐law cloud size distributions.〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Beschreibung: https://bitbucket.org/julien_savre/pycloudfit/src/master/
    Beschreibung: https://doi.org/10.5281/zenodo.7005140
    Schlagwort(e): ddc:551.5 ; Moist convection ; cloud resolving modeling ; cloud size distributions ; cloud merging
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 196
    Publikationsdatum: 2023-07-19
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉Magmatic processes in the continental crust such as crustal convection, melt ascent, magma emplacement, and batholith formation are not well understood. We solve the conservation equations for mass, momentum, and energy for two‐phase flow of melt and solid in 2D, for a thick continental crust heated from below by one or several heat pulses. A simplified binary melting model is incorporated. We systematically vary (a) the retention number, characterizing melt mobility, (b) the intensity of heat pulses applied at the bottom, and (c) the density of the solidified evolved rock. Two characteristic modes are identified: (a) in the “batholith emplacement mode,” segregation is sufficiently strong allowing melts to separate from the convective flow. This melt freezes to form buoyant SiO〈sub〉2〈/sub〉‐rich layers. (b) In the “convective recycling mode,” melts are formed in the lower crust, rise together with the hot rock with little segregation, freeze at shallow depth but are partly recycled back to the lower crust where they remelt. Phase‐change‐driven convection dominates. Mode (a) is favored by high heat input, multiple heat pulses, high melt mobility, and low density of the evolved rock. Mode (b) is favored by less intense heating, less melt mobility, and denser evolved rocks. A scaling law is derived based on the thermal, melt, and compositional Rayleigh numbers and the retention number. The Altiplano‐Puna low‐velocity zone (LVZ) could represent the batholith emplacement mode with buoyant and voluminous magmas causing intense volcanism. The Tibetan LVZ is not associated with intense volcanism and might represent the convective recycling mode.〈/p〉
    Beschreibung: Key Points: Two‐phase flow models of crustal magmatic systems identify two modes: batholith emplacement versus convective recycling of evolved rock.〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉High melt mobility, multiple heating pulses, and low density of solidified evolved rock favor batholith emplacement.〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉The Altiplano‐Puna low‐velocity zone (LVZ) is in the batholith emplacement mode and the Tibetan LVZ is in the convective recycling mode.〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Beschreibung: Deutsche Forschungsgemeinschaft
    Beschreibung: https://doi.org/10.5281/zenodo.7839871
    Schlagwort(e): ddc:552 ; numerical modeling ; diapirism ; magma genesis and partial melting ; magma migration ; physics of magma and magma bodies ; batholith emplacement ; phase‐change‐driven crustal convection ; Altiplano‐Puna Plateau ; Tibetan Plateau
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 197
    Publikationsdatum: 2023-07-19
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉This study investigates the lifetime and temporal evolution of physical properties of trade‐wind cumuli based on tracking individual clouds in observations with the Advanced Baseline Imager aboard the geostationary GOES‐16 satellite during the “ElUcidating the RolE of Cloud–Circulation Coupling in ClimAte” (EUREC〈sup〉4〈/sup〉A) campaign east of Barbados in winter 2020. A first application of our upgraded cloud‐tracking toolbox to measurements with high spatio‐temporal resolution (2 × 2 km〈sup〉2〈/sup〉 and 1 min) provides probability density functions of lifetime and area of clouds that develop as a consequence of meso‐to‐synoptic scale motions. By separately considering clouds that exist during daytime and live in distinct lifetime intervals, we find that shallow marine cumuli live longer when they cover a larger surface area and show higher cloud optical thickness (COT). Besides the effect of COT, the scale of the atmospheric motions with which the clouds interact is also critical to their lifetime.〈/p〉
    Beschreibung: Plain Language Summary: We present a detailed investigation of the lifetime of Caribbean trade‐wind cumulus clouds and the temporal evolution of their physical properties based on geostationary observations with the Advanced Baseline Imager aboard the geostationary GOES‐16 satellite during the “ElUcidating the RolE of Cloud–Circulation Coupling in ClimAte” (EUREC〈sup〉4〈/sup〉A) field experiment in winter 2020. The tracking of 2.7 million individual clouds in measurements with high spatio‐temporal resolution enables the investigation of processes that control the lifetime of shallow marine cumulus (SMC) clouds. Our analysis reveals that SMC clouds live longer when they span over a surface area that exceeds an order of tens of square kilometers. While these clouds show similar median cloud droplet size and number concentration compared to shorter‐lived clouds, they contain more liquid water and, thus, show a COT that is increased by about one third. Besides the effect of COT, we find that the scale of the atmospheric motions with which the clouds interact is also critical to their lifetime.〈/p〉
    Beschreibung: Key Points: First study of the life cycle of shallow marine cumulus based on observations with the Advanced Baseline Imager aboard GOES‐16.〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Confirmation of the double power law in the distribution of cloud lifetime from measurements with a temporal resolution of 1 minute.〈/p〉〈/list-item〉 〈list-item〉 〈p xml:lang="en"〉Cloud lifetime is related to large‐scale circulation and affects cloud optical thickness.〈/p〉〈/list-item〉 〈/list〉 〈/p〉
    Beschreibung: Deutscher Akademischer Austauschdienst http://dx.doi.org/10.13039/501100001655
    Beschreibung: https://observations.ipsl.fr/thredds/catalog/EUREC4A/SATELLITES/GOES-E/2km_01min/2020/catalog.html
    Schlagwort(e): ddc:551.5 ; shallow convection ; trade‐wind cumuli ; life cycle ; EUREC4A ; GOES‐16 ABI
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 198
    Publikationsdatum: 2023-07-19
    Beschreibung: The Miocene mica‐clay deposits of Groß Pampau (northern Germany) are well known for their diverse assemblages of marine mammals. Despite numerous systematic and biostratigraphic studies, an in‐depth palaeoecological analysis of its molluscan assemblages and a comprehensive palaeoenvironmental reconstruction are lacking. Here, we integrate new faunal, sedimentological and geochemical data to reconstruct the marine palaeoecosystem of the Upper Miocene sedimentary succession of Groß Pampau, and to identify the drivers controlling the composition, ecological structure and temporal dynamics of its macrobenthic molluscan assemblages. Fossil evidence, coupled with analyses of clay mineral composition, grain size distribution and geochemical data (total organic carbon, total nitrogen, δ〈sup〉13〈/sup〉C, δ〈sup〉18〈/sup〉O, δ〈sup〉15〈/sup〉N of sediment and shells), suggests a warm–temperate, mesotrophic, low‐energy, offshore marine setting mostly below storm wave base and a pronounced surface‐to‐bottom water temperature gradient. Low variability in sedimentological and geochemical signals indicates generally stable physicochemical conditions, whereas the occurrence of the opportunistic species 〈italic toggle="no"〉Varicorbula gibba〈/italic〉 suggests occasionally unfavourable bottom conditions, possibly related to transient hypoxia. Canonical correspondence analysis indicates that the distribution of molluscan assemblages correlates with total organic carbon and nitrogen content, suggesting organic matter availability at the sea floor as a controlling factor. A pattern of repetitive punctuated stasis of molluscan assemblages is defined by the temporal persistence in taxonomic and ecological composition, occasionally interrupted by shifts to a different faunal configuration. We suggest that both stable environmental conditions and biotic interactions (i.e. the top‐down control exerted by carnivorous gastropods and environmental modification by ubiquitous burrowing deposit feeders) probably contributed to the observed temporal stability.〈/p〉
    Beschreibung: Gemeinnützige Sparkassenstiftung Lübeck
    Beschreibung: https://doi.org/10.5061/dryad.0p2ngf253
    Schlagwort(e): ddc:564 ; Late Miocene ; North Sea Basin ; palaeoenvironment ; molluscan fauna ; stable isotopes
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 199
    Publikationsdatum: 2023-07-19
    Beschreibung: 〈title xmlns:mml="http://www.w3.org/1998/Math/MathML"〉Abstract〈/title〉〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The genesis of floods in large river basins often is complex. Streamflow originating from precipitation and snowmelt and different tributaries can superimpose and cause high water levels, threatening cities and communities along the riverbanks. For better understanding the mechanisms (origin and composition) of flood events in large and complex basins, we capture and share the story behind major historic and projected streamflow peaks in the Rhine River basin. Our analysis is based on hydrological simulations with the mesoscale Hydrological Model forced with both meteorological observations and an ensemble of climate projections. The spatio‐temporal analysis of the flood events includes the assessment and mapping of antecedent liquid precipitation, snow cover changes, generated and routed runoff, areal extents of events, and the above‐average runoff from major sub‐basins up to 10 days before a streamflow peak. We introduce and assess the analytical setup by presenting the flood genesis of the two well‐known Rhine floods that occurred in January 1995 and May 1999. We share our extensive collection of event‐based Rhine River flood genesis, which can be used in‐ and outside the scientific community to explore the complexity and diversity of historic and projected flood genesis in the Rhine basin. An interactive web‐based viewer provides easy access to all major historic and projected streamflow peaks at four locations along the Rhine. The comparison of peak flow genesis depending on different warming levels elucidates the role of changes in snow cover and precipitation characteristics in the (pre‐)Alps for flood hazards along the entire channel of the Rhine. Furthermore, our results suggest a positive correlation between flood magnitudes and areal extents of an event. Further hydro‐climatological research is required to improve the understanding of the climatic impact on the Rhine and beyond.〈/p〉
    Beschreibung: 〈p xmlns:mml="http://www.w3.org/1998/Math/MathML" xml:lang="en"〉The genesis of riverine floods in large river basins often is complex. Streamflow originating from precipitation and snowmelt and different tributaries can superimpose and cause high water levels threatening cities and communities along the riverbanks. In this study, we capture and share the story behind major historic and projected streamflow peaks in the large and complex basin of the Rhine River.〈boxed-text position="anchor" content-type="graphic" id="hyp14918-blkfxd-0001" xml:lang="en"〉 〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:08856087:media:hyp14918:hyp14918-toc-0001"〉
    Beschreibung: https://doi.org/10.5281/zenodo.3239055
    Beschreibung: https://github.com/ERottler/rhine-flood-genesis
    Beschreibung: http://natriskchange.ad.umwelt.uni-potsdam.de:3838/rhine-flood-genesis
    Beschreibung: https://b2share.eudat.eu/records/72d7a4f5d38043d1a137228b39c7ecc3
    Schlagwort(e): ddc:551.46 ; climate change ; flood composition ; flood genesis ; mHM ; model simulations ; quantile extent ; Rhine River ; spatio‐temporal analysis ; web‐based dashboard
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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  • 200
    facet.materialart.
    Unbekannt
    International Union of Crystallography | 5 Abbey Square, Chester, Cheshire CH1 2HU, England
    Publikationsdatum: 2023-07-19
    Beschreibung: Since high‐pressure devices have been used at synchrotron facilities, accurate determination of pressure and temperature in the sample has been a crucial objective, particularly for experiments that simulate the Earth's interior. However, in some cases using a thermocouple may have a high likelihood of failure or is incompatible with a high‐pressure assembly. To address these challenges and similar issues, we aim to expand a previously proposed solution: to jointly estimate pressure and temperature (〈italic〉PT〈/italic〉) through 〈italic〉in situ〈/italic〉 X‐ray diffraction, to cover a wider range of internal 〈italic〉PT〈/italic〉 calibrants tested over larger 〈italic〉PT〈/italic〉 ranges. A modifiable Python‐based software is offered to quickly obtain results. To achieve these aims, 〈italic〉in situ〈/italic〉 large volume press experiments are performed on pellets of intimately mixed powders of a halide (NaCl, KCl, KBr, CsCl) or MgO and a metal (Pt, Re, Mo, W, Ni) in the pressure range 3–11 GPa and temperature range 300–1800 K. Although the pressure range was chosen for practical reasons, it also covers an equally important depth range in the Earth (down to 350 km) for geoscience studies. A thermocouple was used to validate the 〈italic〉PT〈/italic〉 conditions in the cell assemblies. The key results show that choosing the appropriate calibrant materials and using a joint 〈italic〉PT〈/italic〉 estimation can yield surprisingly small uncertainties (〈italic〉i.e.〈/italic〉 〈±0.1 GPa and 〈±50 K). This development is expected to benefit current and future research at extreme conditions, as other materials with high compressibility or high thermal pressure, stable over large 〈italic〉PT〈/italic〉 ranges, may be discovered and used as 〈italic〉PT〈/italic〉 calibrants.〈/p〉
    Beschreibung: Research in high‐pressure devices, such as the diamond anvil cell and the large volume press, requires knowledge of the pressure and temperature in the sample. Here, a large volume press and an internal resistive heater were used to generate high load and heat to various combinations of intimately mixed powders of materials. X‐ray diffraction and custom software were used to jointly estimate the pressures and temperatures in the samples and establish calibrants for 〈italic〉in situ〈/italic〉 experiments at extreme conditions.〈boxed-text position="anchor" content-type="graphic" xml:lang="en"〉〈graphic position="anchor" id="jats-graphic-1" xlink:href="urn:x-wiley:16005775:jsy2vl5008:jsy2vl5008-fig-0001"〉
    Beschreibung: https://gitlab.desy.de/robert.farla/eoscross
    Schlagwort(e): ddc:548 ; equations of state ; X‐ray diffraction ; large volume press ; high pressure ; resistive heating
    Sprache: Englisch
    Materialart: doc-type:article
    Standort Signatur Erwartet Verfügbarkeit
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