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  • 1
    Publication Date: 2024-05-14
    Description: This paper represents a continuation of taxonomic publications on the benthic fauna of polymetallic nodule fields in the eastern Clarion-Clipperton Zone (CCZ) using material collected during baseline environmental survey work targeting two exploration contract areas (“UK-1” and “OMS”) and one Area of Particular Environmental Interest, “APEI-6.” Families Poecilochaetidae Hannerz, 1956 and Spionidae Grube, 1850 of the annelid suborder Spioniformia were studied here. Taxonomic data are presented for 25 species from 98 records as identified by a combination of morphological and genetic approaches. Although sub-optimal morphological condition can prevent new species being formally described, it is essential that morphological, molecular, and voucher data are made available for future surveys. Descriptions of two new species— Poecilochaetus brenkei sp. nov. and Laonice shulseae sp. nov.—increase the number of formally described new annelid species from the areas targeted in this study to 15 and CCZ-wide to 46. We also discuss the commonly reported “cosmopolitan” deep-sea spionid Aurospio dibranchiata Maciolek, 1981, which we show represents several genetically distinct species (three of these from CCZ area alone) but without reliable morphological characters to separate them. Molecular data provide evidence that 15 out of 25 species reported here have a wide distribution within the eastern CCZ and that Aurospio sp. “NHM_2186” and the known species Prionospio amarsupiata Neal & Altamira in Paterson et al. 2016 may be cosmopolitan. Lastly, the molecular data provide insights into relationships within Spioniformia, suggesting that both Poecilochaetidae and Trochochaetidae belong within Spionidae.
    Type: Article , PeerReviewed
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  • 2
    Publication Date: 2024-05-14
    Description: Holothurians are the dominant megabenthic deposit feeders in the Peru Basin (SE Pacific) and feed to various degrees of selectivity on a heterogenous pool of sedimentary detritus, but drivers of feeding selectivity and diet preferences for most holothurian species are unknown. This study reconstructs the diets of 13 holothurian species of the orders Elasipodida, Holothuriida, and Synallactida. Bulk stable isotope analyses (δ13C, δ15N) of holothurian body wall and gut wall tissues, gut contents, and feces were combined with compound-specific stable isotope analyses of amino acids, phospholipid-derived fatty acids, and neutral-lipid-derived fatty acids in the body wall. We further assessed how holothurians in the Peru Basin partition their resources and calculated how much of the daily particulate organic carbon (POC) flux to the area is ingested by them using information about gut contents of nine species. To assess the dependence of holothurians on fresh phytodetritus, we performed in situ pulse-chase experiments using 13C- and 15N-enriched phytodetritus. By measuring the uptake of this phytodetritus in fatty acids and amino acids and by comparing it with the presence of these compounds in the sediment, we calculated net accumulation and net deficiency for specific fatty acids and amino acids and discussed how climate change might affect the dependence on specific compounds. A Sørensen–Dice coefficient-based cluster analysis using data from trophic levels, levels of heterotrophic re-synthesis of amino acids, feeding selectivity, and food sources/diet suggested two major trophic groups with two optional subgroups each. Species-specific traits of locomotion, tentacle morphology, and gut structure likely allow resource partitioning and differences in selectivity among the holothurians, of which a subpopulation of 65% of all specimens can ingest 4 to 27% of the daily POC flux to the Peru Basin. Holothurians are specifically dependent on the uptake of arachidonic acid from phytodetritus, while most essential amino acids are available in the Peru Basin in sufficient concentrations.
    Type: Article , PeerReviewed
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  • 3
    Publication Date: 2024-05-14
    Description: The deep seafloor of the Northeastern Pacific Ocean between the Clarion and Clipperton Fracture Zones (CCZ) hosts large deposits of polymetallic nodules that are of great commercial interest as they are rich in valuable metals such as manganese, nickel, copper and cobalt. However, mining of these nodules has the potential to severely affect the benthic fauna, whose distribution and diversity are still poorly understood. The CCZ is characterized by strong gradients in sea surface productivity and hence changes in the amount of organic carbon reaching the seafloor, decreasing from mesotrophic conditions in the southeast to oligotrophic conditions in the northwest. Uncovering and understanding changes in community composition and structure along this productivity gradient are challenging but important, especially in the context of future mining impacts. Here, we summarize published data on benthic annelids (polychaetes), a major component of macrobenthic communities in the CCZ. Unlike previous studies, we attempt to explore all available data based on both morphology and genetics collected by box corer and epibenthic sledge. In this regard, we specifically aimed to (a) summarize and compare morphological and molecular data in relation to surface water nutrient conditions and (b) provide recommendations to advance the studies of polychaete biodiversity. Although initial studies on polychaetes in the CCZ were performed as far back as the 1970s, there are still large data gaps further explored in our review. For example, most of the current data are from the eastern CCZ, limiting understanding of species ranges across the region. An association between polychaete communities and the available food supply was generally observed in this study. Indeed, mesotrophic conditions supported higher abundance and species richness in polychaetes as a whole, but for certain groups of species, the patterns appear to be opposite — illustrating that relationships are likely more complex at lower taxonomic levels. A better understanding of biogeographical, ecological and evolutionary processes requires a concerted effort involving increased sampling and sharing of data and material to close existing knowledge gaps.
    Type: Article , PeerReviewed
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  • 4
    Publication Date: 2024-05-14
    Description: Many recent ocean modelling studies have demonstrated the added value of enhanced horizontal resolution, although it comes at a high computational cost. However, few modeling studies of ocean-based CDR have been done at high resolution. Here we assess the effects of model resolution on two simulated ocean-based CDR methods, unequilibrated ocean alkalinity enhancement (OAE) and the direct marine capture (DMC) of CO2 from seawater (with assumed permanent storage), in experiments with the FOCI Earth system model. To do this we utilized two FOCI configurations, one with a 1/2° ocean resolution and the other with a 1/10° ocean nest in the N. Atlantic. Both configurations were run in a series of “paired” experiments with identical climate forcing and CDR deployments. We show that model resolution does appear to matter when simulating OAE and DMC. For OAE, parameterization of physical processes in the coarse resolution version of the model appears to overestimate how long alkalized waters stay in contact with the atmosphere and where they are transported. This results in large differences in OAE efficacy with almost twice as much carbon sequestered when the model resolution is coarse. For the DMC simulations, at one site there were clear differences in the compensating CO2 flux induced by DIC removal, which was again higher with a coarse resolution, while at the other site variability was high and differences were difficult to determine. At both DMC sites there were clear differences in circulation with the two model resolutions, and thus on downstream biogeochemistry. We suggest that well resolving ocean physics may be necessary to best calculate unequilibrated OAE and DMC efficacies and side effects. These results should be confirmed using other models and with different resolutions.
    Type: Report , NonPeerReviewed , info:eu-repo/semantics/book
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  • 5
    Publication Date: 2024-05-14
    Description: Mesoscale eddies are common in the subtropical Northwest Pacific, however, relatively little is known about their spatial variability and temporal evolution, and how these impact upper ocean biogeochemistry. Here we investigate these using observations of a cyclonic eddy carried out along four sequential transects. Consistent with previous observations of cyclonic eddies, the eddy core had doming isopycnals, bringing elevated nutrient waters nearer to the surface. However, we also found that the upper layer of the eddy above the nutricline had significantly lower phosphate concentrations within its core relative to its edge. We attributed this to elevated N 2 fixation within the eddy core, which was likely driven by enhanced subsurface iron supply, ultimately resulting in increased phosphate consumption. Eddy‐enhanced N 2 fixation was additionally supported by the elevation of nitrate + nitrite to phosphate ratios below the euphotic zone. Moreover, we observed that while the upward displacement of isopycnals within the eddy core led to an increase in phytoplankton biomass in the lower euphotic zone, there was no significant increase in total phytoplankton biomass across the entire euphotic zone. Cyclonic eddies in the subtropical North Pacific are projected to be becoming more frequent, implying that such dynamics could become increasingly important for regulating nutrient biogeochemistry and ultimately productivity of the region. Key Points Lower phosphate concentrations were observed above the nutricline within the eddy core in comparison to the edge Enhanced N2 fixation within the eddy core is proposed to have driven increased phosphate consumption No substantial total phytoplankton biomass increase was found within the eddy core
    Type: Article , PeerReviewed
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  • 6
    Publication Date: 2024-05-14
    Description: Bericht zum Fachworkshop des Forschungsverbundes GEOSTOR der Forschungsmission CDRmare am 11. Oktober 2023 im Geozentrum Hannover
    Type: Report , NonPeerReviewed
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  • 7
    Publication Date: 2024-05-14
    Description: Abstract
    Description: The dataset is composed of Hyspex (VNIR/SWIR) hyperspectral imagery acquired during airplane overflights on 01. Oktober, 2015 within the Demmin Research Area. The acquisition conditions were cloud free. The dataset includes two mosaics generated based on 9 HySpex flight lines. The dataset also includes Level 2A EnMAP-like imagery simulated using the end-to-end Simulation tool (EeteS). Additionally a soil database focussed on the soil organic carbon content (SOC) with geographic coordinates, texture and spectral information is included.
    Description: Methods
    Description: Nine flight stripes were acquired during an EnMAP GFZ/FUB flight campaign operated by the GFZ using the HySpex VNIR-1600 and HySpex SWIR 320m-e (“HySpex, Norsk Elektro Optikk,” 2015) imaging spectrometers over the DEMMIN test field on 01 October 2015 (10:07-11:01 local time). Over the nine flight stripes, three are located in the Western part of the area over the village of Borrentin and Nossendorf, and six in the Eastern part of the area over the villages of Alt-Tellin, Jarmen and Sassen covering mainly agricultural fields (figure 1). For this campaign the HySpex imaging system was mounted on the Cessna 207T aircraft of the “Freie Universität Berlin” (FUB). The HySpex hyperspectral imaging system is based on two separated push-broom hyperspectral cameras HySpex VNIR-1600 and HySpex SWIR 320m-e which cover the wavelength domain from 0.4-1.0 µm and 1.0-2.5 µm respectively, with a spectral resolution of 3.7 nm (VNIR-1600) and 6.0 nm (SWIR-320m-e). Both sensors were flown with a field of view expander which results in field of view of 33.2° for the VNIR and 26.4° for the SWIR. The position and attitude of the airplane were measured with an AEROcontrol-IId inertial measurement unit (IMU) with available data rates of 256 Hz in combination with a Novatel OEM4 - g2 GPS receiver. The HySpex sensors (VNIR, SWIR) and DGPS/IMU sensors were arranged on an active stabilization platform (SM2000 ). The entire airborne campaign was conducted at a mean altitude of 2500m which results in a mean ground sampling distance (GSD) of 1.9 m for the VNIR and 3.8 m for the SWIR. After the preprocessing of the HySpex data (georectification, sensor co-registration, atmospheric correction, mosaicking) the hyperspectral data cube consists of a total of 408/390 bands resampled to 4m pixel resolution. The overflight encompassed an area of approximately 23000 ha.
    Description: Other
    Description: The Environmental Mapping and Analysis Program (EnMAP) is a German hyperspectral satellite mission that aims at monitoring and characterizing the Earth’s environment on a global scale. EnMAP serves to measure and model key dynamic processes of the Earth’s ecosystems by extract-ing geochemical, biochemical and biophysical parameters, which provide information on the status and evolution of various terrestrial and aquatic ecosystems. In the frame of the EnMAP preparatory phase, pre-flight campaigns including airborne and in-situ measurements in different environments and for several application fields are being conducted. The main purpose of these campaigns is to support the development of scientific applications for EnMAP. In addition, the acquired data are input in the EnMAP end-to-end simulation tool (EeteS) and are employed to test data pre-processing and calibration-validation methods. The campaign data are made freely available to the scientific community under a Creative Commons Attribution 4.0 International License. An overview of all available data is provided in in the EnMAP Flight Campaigns Metadata Portal (http://www.enmap.org/?q=flights).
    Keywords: Hyperspectral Imagery ; Soil ; Landuse ; Agricultur ; agriculture 〉 agricultural method ; Earth Remote Sensing Instruments 〉 Passive Remote Sensing 〉 Spectrometers/Radiometers 〉 Hyperspectral Spectrometers/Radiometers ; EARTH SCIENCE 〉 AGRICULTURE 〉 SOILS 〉 SOIL CHEMISTRY ; EARTH SCIENCE 〉 BIOSPHERE 〉 VEGETATION ; land 〉 world 〉 Europe 〉 Western Europe ; pedosphere 〉 soil
    Type: Dataset , Dataset
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  • 8
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    In:  IGARSS 2023 - 2023 IEEE International Geoscience and Remote Sensing Symposium: Proceedings
    Publication Date: 2024-05-14
    Description: Precipitation nowcasting (up to a few hours) remains a challenge due to the highly complex local interactions that need to be captured accurately. Convolutional Neural Networks rely on convolutional kernels convolving with grid data and the extracted features are trapped by limited receptive field, typically expressed in excessively smooth output compared to ground truth. Thus they lack the capacity to model complex spatial relationships among the grids. Geometric deep learning aims to generalize neural network models to non-Euclidean domains. Such models are more flexible in defining nodes and edges and can effectively capture dynamic spatial relationship among geographical grids. Motivated by this, we explore a geometric deep learning-based temporal Graph Convolutional Network (GCN) for precipitation nowcasting. The adjacency matrix that simulates the interactions among grid cells is learned automatically by minimizing the L1 loss between prediction and ground truth pixel value during the training procedure. Then, the spatial relationship is refined by GCN layers while the temporal information is extracted by 1D convolution with various kernel lengths. The neighboring information is fed as auxiliary input layers to improve the final result. We test the model on sequences of radar reflectivity maps over the Trento/Italy area. The results show that GCNs improves the effectiveness of modeling the local details of the cloud profile as well as the prediction accuracy by achieving decreased error measures.
    Language: English
    Type: info:eu-repo/semantics/bookPart
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  • 9
    Publication Date: 2024-05-14
    Description: Die Entscheidung für den Austausch oder Ersatz eines Heizsystems ist eine, die für mehr als ein Jahrzehnt getroffen wird. Oftmals berücksichtigen Verbraucherinnen und Verbraucher dabei vor allem die einmal anfallende Einbau-Investition. Die Kosten über den gesamten Lebenszyklus sind deutlich schwerer zu ermitteln und unsicher, daher werden sie häufig zu wenig in die finanzielle Überlegung mit einbezogen. In einer neuen Analyse haben Ariadne-Forschende berechnet, wie hoch unterm Strich die Kosten für verschiedene Heiztechniken in bestehenden Wohngebäuden über einen Zeitraum von 20 Jahren angesichts zukünftiger Energieträgerpreise sowie der zu erwartenden CO2-Preisentwicklung sind.
    Language: German
    Type: info:eu-repo/semantics/report
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  • 10
    Publication Date: 2024-05-14
    Description: Global flood impacts have risen in recent decades. While increasing exposure was the dominant driver of surging impacts, counteracting vulnerability reductions have been detected, but were too weak to reverse this trend. To assess the ongoing progress on vulnerability reduction, we combine a recently available dataset of flooded areas derived from satellite imagery for 913 events with four global disaster databases and socio-economic data. Event-specific flood vulnerabilities for assets, fatalities and displacements reveal a lack of progress in reducing global flood vulnerability from 2000—2018. We examine the relationship between vulnerabilities and human development, inequality, flood exposure and local structural characteristics. We find that vulnerability levels are significantly lower in areas with good structural characteristics and significantly higher in low developed areas. However, socio-economic development was insufficient to reduce vulnerabilities over the study period. Nevertheless, the strong correlation between vulnerability and structural characteristics suggests further potential for adaptation through vulnerability reduction.
    Language: English
    Type: info:eu-repo/semantics/article
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