ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Artikel  (40.755)
  • Wiley-Blackwell  (26.896)
  • Blackwell Publishing Ltd  (9.321)
  • American Meteorological Society
  • Annual Reviews
  • 2020-2024  (58)
  • 1965-1969  (40.697)
Sammlung
Erscheinungszeitraum
Jahr
Zeitschrift
  • 1
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Journal of Climate, American Meteorological Society, 35(23), pp. 7811-7831, ISSN: 0894-8755
    Publikationsdatum: 2023-06-23
    Beschreibung: Numerical simulations allow us to gain a comprehensive understanding of the underlying mechanisms of past, present, and future climate changes. The mid-Holocene (MH) and the last interglacial (LIG) were the two most recent warm episodes of Earth’s climate history and are the focus of paleoclimate research. Here, we present results of MH and LIG simulations with two versions of the state-of-the-art Earth system model AWI-ESM. Most of the climate changes in MH and LIG compared to the preindustrial era are agreed upon by the two model versions, including 1) enhanced seasonality in surface temperature that is driven by the redistribution of seasonal insolation; 2) a northward shift of the intertropical convergence zone (ITCZ) and tropical rain belt; 3) a reduction in annual mean Arctic sea ice concentration; 4) weakening and northward displacement of the Northern Hemisphere Hadley circulation, which is related to the decrease and poleward shift of the temperature gradient from the subtropical to the equator in the Northern Hemisphere; 5) a westward shift of the Indo-Pacific Walker circulation due to anomalous warming over the Eurasia and North Africa during boreal summer; and 6) an expansion and intensification of Northern Hemisphere summer monsoon rainfall, with the latter being dominated by the dynamic component of moisture budget (i.e., the strengthening of wind circulation). However, the simulated responses of the Atlantic meridional overturning circulation (AMOC) in the two models yield different results for both the LIG and the MH. AMOC anomalies between the warm interglacial and preindustrial periods are associated with changes in North Atlantic westerly winds and stratification of the water column at the North Atlantic due to changes in ocean temperature, salinity, and density.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Publikationsdatum: 2023-02-25
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(11), (2022): 2841–2852, https://doi.org/10.1175/jpo-d-22-0025.1.
    Beschreibung: Prediction of rapid intensification in tropical cyclones prior to landfall is a major societal issue. While air–sea interactions are clearly linked to storm intensity, the connections between the underlying thermal conditions over continental shelves and rapid intensification are limited. Here, an exceptional set of in situ and satellite data are used to identify spatial heterogeneity in sea surface temperatures across the inner core of Hurricane Sally (2020), a storm that rapidly intensified over the shelf. A leftward shift in the region of maximum cooling was observed as the hurricane transited from the open gulf to the shelf. This shift was generated, in part, by the surface heat flux in conjunction with the along- and across-shelf transport of heat from storm-generated coastal circulation. The spatial differences in the sea surface temperatures were large enough to potentially influence rapid intensification processes suggesting that coastal thermal features need to be accounted for to improve storm forecasting as well as to better understand how climate change will modify interactions between tropical cyclones and the coastal ocean.
    Beschreibung: This research was made possible by the NOAA RESTORE Science Program (NA17NOS4510101 and NA19NOS4510194) and the NASA Physical Oceanography program (80NSSC21K0553 and WBS 281945.02.25.04.67) and NOAA IOOS program via GCOOS (NA16NOS0120018). The authors declare that they have no competing interests.
    Schlagwort(e): Seas/gulfs/bays ; Atmosphere–ocean interaction ; Currents ; Tropical cyclones ; Buoy observations ; In situ oceanic observations
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Publikationsdatum: 2023-02-25
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(8), (2022): 1797–1815, https://doi.org/10.1175/JPO-D-21-0288.1.
    Beschreibung: Intruding slope water is a major source of nutrients to sustain the high biological productivity in the Gulf of Maine (GoM). Slope water intrusion into the GoM is affected by Gulf Stream warm-core rings (WCRs) impinging onto the nearby shelf edge. This study combines long-term mooring measurements, satellite remote sensing data, an idealized numerical ocean model, and a linear coastal-trapped wave (CTW) model to examine the impact of WCRs on slope water intrusion into the GoM through the Northeast Channel. Analysis of satellite sea surface height and temperature data shows that the slope sea region off the GoM is a hotspot of ring activities. A significant linear relationship is found between interannual variations of ring activities in the slope sea region off the GoM and bottom salinity at the Northeast Channel, suggesting the importance of WCRs in modulating variability of intruding slope water. Analysis of the mooring data reveals enhanced slope water intrusion through bottom-intensified along-channel flow following impingements of WCRs on the nearby shelf edge. Numerical simulations qualitatively reproduce the observed WCR impingement processes and associated episodic enhancement of slope water intrusion in the Northeast Channel. Diagnosis of the model result indicates that baroclinic CTWs excited by the ring–topography interaction are responsible for the episodically intensified subsurface along-channel inflow, which carries more slope water into the GoM. A WCR that impinges onto the shelf edge to the northeast of the Northeast Channel tends to generate stronger CTWs and cause stronger enhancement of the slope water intrusion into the GoM.
    Beschreibung: This study is supported by the National Science Foundation through Grant OCE-1634965.
    Schlagwort(e): Continental shelf/slope ; Channel flows ; Mesoscale processes ; In situ oceanic observations ; Satellite observations ; Numerical analysis/modeling
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Journal of Climate, American Meteorological Society, pp. 1-40, ISSN: 0894-8755
    Publikationsdatum: 2023-09-04
    Beschreibung: 〈jats:title〉Abstract〈/jats:title〉 〈jats:p〉Tipping points in the Earth system describe critical thresholds beyond which a single component, part of the system, or the system as a whole changes from one stable state to another. In the present-day Southern Ocean, the Weddell Sea constitutes an important dense-water formation site, associated with efficient deep-ocean carbon and oxygen transfer and low ice-shelf basal melt rates. Here, a regime shift will occur when continental shelves are continuously flushed with warm, oxygen-poor offshore waters from intermediate depth, leading to less efficient deep-ocean carbon and oxygen transfer and higher ice-shelf basal melt rates. We use a global ocean–biogeochemistry model including ice-shelf cavities and an eddy-permitting grid in the southern Weddell Sea to address the susceptibility of this region to such a system change for four 21〈jats:sup〉st〈/jats:sup〉-century emission scenarios. Assessing the projected changes in shelf–open ocean density gradients, bottom-water properties, and on-shelf heat transport, our results indicate that the Weddell Sea undergoes a regime shift by 2100 in the highest-emission scenario SSP5-8.5, but not yet in the lower-emission scenarios. The regime shift is imminent by 2100 in the scenarios SSP3-7.0 and SSP2-4.5, but avoidable under the lowest-emission scenario SSP1-2.6. While shelf-bottom waters freshen and acidify everywhere, bottom waters in the Filchner Trough undergo accelerated warming and deoxygenation following the system change, with implications for local ecosystems and ice-shelf basal melt. Additionally, deep-ocean carbon and oxygen transfer decline, implying that the local changes ultimately affect ocean circulation, climate, and ecosystems globally.〈/jats:p〉
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Bulletin of the American Meteorological Society, American Meteorological Society, 104(1), pp. e208-e242, ISSN: 0003-0007
    Publikationsdatum: 2023-04-26
    Beschreibung: Mechanisms behind the phenomenon of Arctic amplification are widely discussed. To contribute to this debate, the (AC)3 project was established in 2016 (www.ac3-tr.de/). It comprises modeling and data analysis efforts as well as observational elements. The project has assembled a wealth of ground-based, airborne, shipborne, and satellite data of physical, chemical, and meteorological properties of the Arctic atmosphere, cryosphere, and upper ocean that are available for the Arctic climate research community. Short-term changes and indications of long-term trends in Arctic climate parameters have been detected using existing and new data. For example, a distinct atmospheric moistening, an increase of regional storm activities, an amplified winter warming in the Svalbard and North Pole regions, and a decrease of sea ice thickness in the Fram Strait and of snow depth on sea ice have been identified. A positive trend of tropospheric bromine monoxide (BrO) column densities during polar spring was verified. Local marine/biogenic sources for cloud condensation nuclei and ice nucleating particles were found. Atmospheric–ocean and radiative transfer models were advanced by applying new parameterizations of surface albedo, cloud droplet activation, convective plumes and related processes over leads, and turbulent transfer coefficients for stable surface layers. Four modes of the surface radiative energy budget were explored and reproduced by simulations. To advance the future synthesis of the results, cross-cutting activities are being developed aiming to answer key questions in four focus areas: lapse rate feedback, surface processes, Arctic mixed-phase clouds, and airmass transport and transformation.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Publikationsdatum: 2023-01-27
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(8), (2022): 1705-1730, https://doi.org/10.1175/jpo-d-21-0243.1.
    Beschreibung: Formation and evolution of barrier layers (BLs) and associated temperature inversions (TIs) were investigated using a 1-yr time series of oceanic and air–sea surface observations from three moorings deployed in the eastern Pacific fresh pool. BL thickness and TI amplitude showed a seasonality with maxima in boreal summer and autumn when BLs were persistently present. Mixed layer salinity (MLS) and mixed layer temperature (MLT) budgets were constructed to investigate the formation mechanism of BLs and TIs. The MLS budget showed that BLs were initially formed in response to horizontal advection of freshwater in boreal summer and then primarily maintained by precipitation. The MLT budget revealed that penetration of shortwave radiation through the mixed layer base is the dominant contributor to TI formation through subsurface warming. Geostrophic advection is a secondary contributor to TI formation through surface cooling. When the BL exists, the cooling effect from entrainment and the warming effect from detrainment are both significantly reduced. In addition, when the BL is associated with the presence of a TI, entrainment works to warm the mixed layer. The presence of BLs makes the shallower mixed layer more sensitive to surface heat and freshwater fluxes, acting to enhance the formation of TIs that increase the subsurface warming via shortwave penetration.
    Beschreibung: SK is supported by JSPS Overseas Research Fellowships. JS and SK are supported by NASA Grant 80NSSC18K1500. JTF and the mooring deployment were funded by NASA Grants NNX15AG20G and 80NSSC18K1494. DZ is supported by NASA Grant 80NSSC18K1499. This publication is partially funded by the Cooperative Institute for Climate, Ocean, and Ecosystem Studies (CICOES) under NOAA Cooperative Agreement NA20OAR4320271, Contribution 2021-1152. This is PMEL Contribution 5268.
    Beschreibung: 2023-01-27
    Schlagwort(e): Ocean ; North Pacific Ocean ; Tropics ; Entrainment ; Oceanic mixed layer ; Salinity
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Publikationsdatum: 2023-02-01
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(8), (2022): 1927-1943, https://doi.org/10.1175/jpo-d-21-0124.1.
    Beschreibung: The Galápagos Archipelago lies on the equator in the path of the eastward flowing Pacific Equatorial Undercurrent (EUC). When the EUC reaches the archipelago, it upwells and bifurcates into a north and south branch around the archipelago at a latitude determined by topography. Since the Coriolis parameter (f) equals zero at the equator, strong velocity gradients associated with the EUC can result in Ertel potential vorticity (Q) having sign opposite that of planetary vorticity near the equator. Observations collected by underwater gliders deployed just west of the Galápagos Archipelago during 2013–16 are used to estimate Q and to diagnose associated instabilities that may impact the Galápagos Cold Pool. Estimates of Q are qualitatively conserved along streamlines, consistent with the 2.5-layer, inertial model of the EUC by Pedlosky. The Q with sign opposite of f is advected south of the Galápagos Archipelago when the EUC core is located south of the bifurcation latitude. The horizontal gradient of Q suggests that the region between 2°S and 2°N above 100 m is barotropically unstable, while limited regions are baroclinically unstable. Conditions conducive to symmetric instability are observed between the EUC core and the equator and within the southern branch of the undercurrent. Using 2-month and 3-yr averages, e-folding time scales are 2–11 days, suggesting that symmetric instability can persist on those time scales.
    Beschreibung: This work was supported by the National Science Foundation (Grants OCE-1232971 and OCE-1233282), the NASA Earth and Space Science Fellowship Program (Grant 80NSSC17K0443), and the Global Ocean Monitoring and Observing Program of the National Oceanographic and Atmospheric Administration (NA13OAR4830216). Color maps are from Thyng et al. (2016).
    Beschreibung: 2023-02-01
    Schlagwort(e): Currents ; In situ oceanic observations ; Instability ; Mixing ; Ocean dynamics ; Pacific Ocean ; Potential vorticity ; Tropics
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Publikationsdatum: 2023-02-01
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 39(8), (2022): 1183-1198, https://doi.org/10.1175/jtech-d-21-0068.1.
    Beschreibung: Horizontal kinematic properties, such as vorticity, divergence, and lateral strain rate, are estimated from drifter clusters using three approaches. At submesoscale horizontal length scales O(1–10)km, kinematic properties become as large as planetary vorticity f, but challenging to observe because they evolve on short time scales O(hourstodays). By simulating surface drifters in a model flow field, we quantify the sources of uncertainty in the kinematic property calculations due to the deformation of cluster shape. Uncertainties arise primarily due to (i) violation of the linear estimation methods and (ii) aliasing of unresolved scales. Systematic uncertainties (iii) due to GPS errors, are secondary but can become as large as (i) and (ii) when aspect ratios are small. Ideal cluster parameters (number of drifters, length scale, and aspect ratio) are determined and error functions estimated empirically and theoretically. The most robust method—a two-dimensional, linear least squares fit—is applied to the first few days of a drifter dataset from the Bay of Bengal. Application of the length scale and aspect-ratio criteria minimizes errors (i) and (ii), and reduces the total number of clusters and so computational cost. The drifter-estimated kinematic properties map out a cyclonic mesoscale eddy with a surface, submesoscale fronts at its perimeter. Our analyses suggest methodological guidance for computing the two-dimensional kinematic properties in submesoscale flows, given the recently increasing quantity and quality of drifter observations, while also highlighting challenges and limitations.
    Beschreibung: This research was supported by the Office of Naval Research (ONR) Departmental Research Initiative ASIRI under Grant N00014-13-1-0451 (SE and AM) and Grant N00014-13-1-0477 (VH and LC). The authors thank the captain and crew of the R/V Roger Revelle, and Andrew Lucas with the Multiscale Ocean Dynamics group at the Scripps Institution for Oceanography for providing the FastCTD data collected in 2015, which was supported by ONR Grant N00014-13-1-0489, as well as Eric D’Asaro for helpful discussions and Lance Braasch for assistance with the drifter dataset. AM and SE further thank NSF (Grant OCE-I434788) and ONR (Grant N00014-16-1-2470) for support. VH and LC were additionally supported by ONR Grants N00014-15-1-2286, N00014-14-1-0183, N00014-19-1-26-91 and NOAA Global Drifter Program (GDP) Grant NA15OAR4320071.
    Beschreibung: 2023-02-01
    Schlagwort(e): Indian Ocean ; Eddies ; Frontogenesis/frontolysis ; Fronts ; Lagrangian circulation/transport ; Ocean circulation ; Ocean dynamics
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Publikationsdatum: 2023-02-01
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 35(17), (2022): 5465-5482, https://doi.org/10.1175/jcli-d-21-0671.1.
    Beschreibung: Understanding the contribution of ocean circulation to glacial–interglacial climate change is a major focus of paleoceanography. Specifically, many have tried to determine whether the volumes and depths of Antarctic- and North Atlantic–sourced waters in the deep ocean changed at the Last Glacial Maximum (LGM; ∼22–18 kyr BP) when atmospheric pCO2 concentrations were 100 ppm lower than the preindustrial. Measurements of sedimentary geochemical proxies are the primary way that these deep ocean structural changes have been reconstructed. However, the main proxies used to reconstruct LGM Atlantic water mass geometry provide conflicting results as to whether North Atlantic–sourced waters shoaled during the LGM. Despite this, a number of idealized modeling studies have been advanced to describe the physical processes resulting in shoaled North Atlantic waters. This paper aims to critically assess the approaches used to determine LGM Atlantic circulation geometry and lay out best practices for future work. We first compile existing proxy data and paleoclimate model output to deduce the processes responsible for setting the ocean distributions of geochemical proxies in the LGM Atlantic Ocean. We highlight how small-scale mixing processes in the ocean interior can decouple tracer distributions from the large-scale circulation, complicating the straightforward interpretation of geochemical tracers as proxies for water mass structure. Finally, we outline promising paths toward ascertaining the LGM circulation structure more clearly and deeply.
    Beschreibung: S.K.H. was supported by the Investment in Science Fund at WHOI and the John E. and Anne W. Sawyer Endowed Fund in Support of Scientific Staff. F.J.P. was supported by a Stanback Postdoctoral Fellowship at Caltech.
    Beschreibung: 2023-02-01
    Schlagwort(e): Diapycnal mixing ; Meridional overturning circulation ; Ocean circulation
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Publikationsdatum: 2023-02-17
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 39(10), (2022): 1525–1539, https://doi.org/10.1175/jtech-d-21-0186.1.
    Beschreibung: The static and dynamic performances of the RBRargo3 are investigated using a combination of laboratory-based and in situ datasets from floats deployed as part of an Argo pilot program. Temperature and pressure measurements compare well to co-located reference data acquired from shipboard CTDs. Static accuracy of salinity measurements is significantly improved using 1) a time lag for temperature, 2) a quadratic pressure dependence, and 3) a unit-based calibration for each RBRargo3 over its full pressure range. Long-term deployments show no significant drift in the RBRargo3 accuracy. The dynamic response of the RBRargo3 demonstrates the presence of two different adjustment time scales: a long-term adjustment O(120) s, driven by the temperature difference between the interior of the conductivity cell and the water, and a short-term adjustment O(5–10) s, associated to the initial exchange of heat between the water and the inner ceramic. Corrections for these effects, including dependence on profiling speed, are developed.
    Schlagwort(e): Data processing/distribution ; In situ oceanic observations ; Profilers ; Oceanic
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 11
    Publikationsdatum: 2023-02-28
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(12),(2022): 3199-3219, https://doi.org/10.1175/jpo-d-22-0009.1.
    Beschreibung: The abyssal overturning circulation is thought to be primarily driven by small-scale turbulent mixing. Diagnosed water-mass transformations are dominated by rough topography “hotspots,” where the bottom enhancement of mixing causes the diffusive buoyancy flux to diverge, driving widespread downwelling in the interior—only to be overwhelmed by an even stronger upwelling in a thin bottom boundary layer (BBL). These water-mass transformations are significantly underestimated by one-dimensional (1D) sloping boundary layer solutions, suggesting the importance of three-dimensional physics. Here, we use a hierarchy of models to generalize this 1D boundary layer approach to three-dimensional eddying flows over realistically rough topography. When applied to the Mid-Atlantic Ridge in the Brazil Basin, the idealized simulation results are roughly consistent with available observations. Integral buoyancy budgets isolate the physical processes that contribute to realistically strong BBL upwelling. The downward diffusion of buoyancy is primarily balanced by upwelling along the sloping canyon sidewalls and the surrounding abyssal hills. These flows are strengthened by the restratifying effects of submesoscale baroclinic eddies and by the blocking of along-ridge thermal wind within the canyon. Major topographic sills block along-thalweg flows from restratifying the canyon trough, resulting in the continual erosion of the trough’s stratification. We propose simple modifications to the 1D boundary layer model that approximate each of these three-dimensional effects. These results provide local dynamical insights into mixing-driven abyssal overturning, but a complete theory will also require the nonlocal coupling to the basin-scale circulation.
    Beschreibung: We acknowledge funding support from National Science Foundation Awards 1536515, 1736109, and 2149080. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant 174530.
    Beschreibung: 2023-05-18
    Schlagwort(e): Abyssal circulation ; Diapycnal mixing ; Meridional overturning circulation ; Topographic effects ; Upwelling/downwelling ; Bottom currents/bottom water
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 12
    Publikationsdatum: 2023-02-28
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(6), (2022): 1091–1110, https://doi.org/10.1175/JPO-D-21-0068.1.
    Beschreibung: Hundreds of full-depth temperature and salinity profiles collected by Deepglider autonomous underwater vehicles (AUVs) in the North Atlantic reveal robust signals in eddy isopycnal vertical displacement and horizontal current throughout the entire water column. In separate glider missions southeast of Bermuda, subsurface-intensified cold, fresh coherent vortices were observed with velocities exceeding 20 cm s−1 at depths greater than 1000 m. With vertical resolution on the order of 20 m or less, these full-depth glider slant profiles newly permit estimation of scaled vertical wavenumber spectra from the barotropic through the 40th baroclinic mode. Geostrophic turbulence theory predictions of spectral slopes associated with the forward enstrophy cascade and proportional to inverse wavenumber cubed generally agree with glider-derived quasi-universal spectra of potential and kinetic energy found at a variety of locations distinguished by a wide range of mean surface eddy kinetic energy. Water-column average spectral estimates merge at high vertical mode number to established descriptions of internal wave spectra. Among glider mission sites, geographic and seasonal variability implicate bottom drag as a mechanism for dissipation, but also the need for more persistent sampling of the deep ocean.
    Beschreibung: This work was funded by NSF Grant 1736217 and would not have been possible without the help of Kirk O’Donnell, James Bennett, Noel Pelland, and all contributors to Deepglider development. We additionally thank the captain crew of the R/V Atlantic Explorer and the BATS team at the Bermuda Institute of Ocean Sciences, particularly Rod Johnson, as well as Seakeepers International for their professionalism, capability, and generous assistance in deploying and recovering gliders.
    Schlagwort(e): North Atlantic Ocean ; Eddies ; Mesoscale processes ; Turbulence ; Energy transport ; In situ oceanic observations ; Oceanic variability
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 13
    facet.materialart.
    Unbekannt
    Annual Reviews
    Publikationsdatum: 2023-02-28
    Beschreibung: © The Author(s), 2023. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Timmermans, M.-L., & Toole, J. The Arctic Ocean’s Beaufort Gyre. Annual Review of Marine Science, 15(1), (2023): 223-248, https://doi.org/10.1146/annurev-marine-032122-012034.
    Beschreibung: The Arctic Ocean's Beaufort Gyre is a dominant feature of the Arctic system, a prominent indicator of climate change, and possibly a control factor for high-latitude climate. The state of knowledge of the wind-driven Beaufort Gyre is reviewed here, including its forcing, relationship to sea-ice cover, source waters, circulation, and energetics. Recent decades have seen pronounced change in all elements of the Beaufort Gyre system. Sea-ice losses have accompanied an intensification of the gyre circulation and increasing heat and freshwater content. Present understanding of these changes is evaluated, and time series of heat and freshwater content are updated to include the most recent observations.
    Beschreibung: Support was provided by the National Science Foundation Office of Polar Programs and the Office of Naval Research.
    Schlagwort(e): Arctic Ocean ; Beaufort Gyre ; Circulation ; Sea ice ; Freshwater ; Ocean heat content
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 14
    Publikationsdatum: 2023-03-02
    Beschreibung: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(12), (2022): 3221–3240, https://doi.org/10.1175/jpo-d-22-0010.1.
    Beschreibung: Small-scale mixing drives the diabatic upwelling that closes the abyssal ocean overturning circulation. Indirect microstructure measurements of in situ turbulence suggest that mixing is bottom enhanced over rough topography, implying downwelling in the interior and stronger upwelling in a sloping bottom boundary layer. Tracer release experiments (TREs), in which inert tracers are purposefully released and their dispersion is surveyed over time, have been used to independently infer turbulent diffusivities—but typically provide estimates in excess of microstructure ones. In an attempt to reconcile these differences, Ruan and Ferrari derived exact tracer-weighted buoyancy moment diagnostics, which we here apply to quasi-realistic simulations. A tracer’s diapycnal displacement rate is exactly twice the tracer-averaged buoyancy velocity, itself a convolution of an asymmetric upwelling/downwelling dipole. The tracer’s diapycnal spreading rate, however, involves both the expected positive contribution from the tracer-averaged in situ diffusion as well as an additional nonlinear diapycnal distortion term, which is caused by correlations between buoyancy and the buoyancy velocity, and can be of either sign. Distortion is generally positive (stretching) due to bottom-enhanced mixing in the stratified interior but negative (contraction) near the bottom. Our simulations suggest that these two effects coincidentally cancel for the Brazil Basin Tracer Release Experiment, resulting in negligible net distortion. By contrast, near-bottom tracers experience leading-order distortion that varies in time. Errors in tracer moments due to realistically sparse sampling are generally small (〈20%), especially compared to the O(1) structural errors due to the omission of distortion effects in inverse models. These results suggest that TREs, although indispensable, should not be treated as “unambiguous” constraints on diapycnal mixing.
    Beschreibung: We acknowledge funding support from National Science Foundation Awards 1536515 and 1736109. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant 174530. This research is also supported by the NOAA Climate and Global Change Postdoctoral Fellowship Program, administered by UCAR’s Cooperative Programs for the Advancement of Earth System Science (CPAESS) under Award NA18NWS4620043B.
    Beschreibung: 2023-05-18
    Schlagwort(e): Diapycnal mixing ; Diffusion ; Upwelling/downwelling ; Bottom currents/bottom water ; Tracers
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 15
    facet.materialart.
    Unbekannt
    Annual Reviews
    In:  EPIC3Annual Review of Marine Science, Annual Reviews, 16(1), pp. 417-441, ISSN: 1941-1405
    Publikationsdatum: 2024-03-01
    Beschreibung: The genus Phaeocystis is globally distributed, with blooms commonly occurring on continental shelves. This unusual phytoplankter has two major morphologies: solitary cells and cells embedded in a gelatinous matrix. Only colonies form blooms. Their large size (commonly 2 mm but up to 3 cm) and mucilaginous envelope allow the colonies to escape predation, but data are inconsistent as to whether colonies are grazed. Cultured Phaeocystis can also inhibit the growth of co-occurring phytoplankton or the feeding of potential grazers. Colonies and solitary cells use nitrate as a nitrogen source, although solitary cells can also grow on ammonium. Phaeocystis colonies might be a major contributor to carbon flux to depth, but in most cases, colonies are rapidly remineralized in the upper 300 m. The occurrence of large Phaeocystis blooms is often associated with environments with low and highly variable light and high nitrate levels, with Phaeocystis antarctica blooms being linked additionally to high iron availability. Emerging results indicate that different clones of Phaeocystis have substantial genetic plasticity, which may explain its appearance in a variety of environments. Given the evidence of Phaeocystis appearing in new systems, this trend will likely continue in the near future.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , peerRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 16
    facet.materialart.
    Unbekannt
    Wiley-Blackwell
    In:  EPIC3Reviews in Aquaculture, Wiley-Blackwell, ISSN: 1753-5123
    Publikationsdatum: 2024-05-06
    Beschreibung: Mass mortality events (MMEs) are defined as the death of large numbers of fish over a short period of time. These events can result in catastrophic losses to the Atlantic salmon aquaculture industry and the local economy. However, they are challenging to understand because of their relative infrequency and the high number of potential factors involved. As a result, the causes and consequences of MMEs in Atlantic salmon aquaculture are not well understood. In this study, we developed a structural network of causal risk factors for MMEs for aquaculture and the communities that depend on Atlantic salmon aquaculture. Using the Interpretive Structural Modeling (ISM) technique, we analysed the causes of Atlantic salmon mass mortalities due to environmental (abiotic), biological (biotic) and nutritional risk factors. The consequences of MMEs were also assessed for the occupational health and safety of aquaculture workers and their implications for the livelihoods of local communities. This structural network deepens our understanding of MMEs and points to management actions and interventions that can help mitigate mass mortalities. MMEs are typically not the result of a single risk factor but are caused by the systematic interaction of risk factors related to the environment, fish diseases, feeding/nutrition and cage-site management. Results also indicate that considerations of health and safety risk, through pre- and post-event risk assessments, may help to minimize workplace injuries and eliminate potential risks of human fatalities. Company and government assisted socio-economic measures could help mitigate post-mass mortality impacts. Appropriate and timely management actions may help reduce MMEs at Atlantic salmon cage sites and minimize the physical and social vulnerabilities of workers and local communities.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 17
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Journal of Physical Oceanography, American Meteorological Society, 54(4), pp. 1003-1018, ISSN: 0022-3670
    Publikationsdatum: 2024-04-25
    Beschreibung: Coastal upwelling, driven by alongshore winds and characterized by cold sea surface temperatures and high upper-ocean nutrient content, is an important physical process sustaining some of the oceans’ most productive ecosystems. To fully understand the ocean properties in eastern boundary upwelling systems, it is important to consider the depth of the source waters being upwelled, as it affects both the SST and the transport of nutrients toward the surface. Here, we construct an upwelling source depth distribution for parcels at the surface in the upwelling zone. We do so using passive tracers forced at the domain boundary for every model depth level to quantify their contributions to the upwelled waters. We test the dependence of this distribution on the strength of the wind stress and stratification using high-resolution regional ocean simulations of an idealized coastal upwelling system. We also present an efficient method for estimating the mean upwelling source depth. Furthermore, we show that the standard deviation of the upwelling source depth distribution increases with increasing wind stress and decreases with increasing stratification. These results can be applied to better understand and predict how coastal upwelling sites and their surface properties have and will change in past and future climates.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 18
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Journal of Climate, American Meteorological Society, 37(6), pp. 2059-2080, ISSN: 0894-8755
    Publikationsdatum: 2024-04-22
    Beschreibung: Heat stress is projected to intensify with global warming, causing significant socioeconomic impacts and threatening human health. Wet-bulb temperature (WBT), which combines temperature and humidity effects, is a useful indicator for assessing regional and global heat stress variability and trends. However, the variations of European WBT and their underlying mechanisms remain unclear. Using observations and reanalysis datasets, we demonstrate a remarkable warming of summer WBT during the period 1958–2021 over Europe. Specifically, the European summer WBT has increased by over 1.08C in the past 64 years. We find that the increase in European summer WBT is driven by both near-surface warming temperatures and increasing atmospheric moisture content. We identify four dominant modes of European summer WBT variability and investigate their linkage with the large-scale atmospheric circulation and sea surface temperature anomalies. The first two leading modes of the European WBT variability exhibit prominent interdecadal to long-term variations, mainly driven by a circumglobal wave train and concurrent sea surface temperature variations. The last two leading modes of European WBT variability mainly show interannual variations, indicating a direct and rapid response to large-scale atmospheric dynamics and nearby sea surface temperature variations. Further analysis shows the role of global warming and changes in midlatitude circulations in the variations of summer WBT. Our findings can enhance the understanding of plausible drivers of heat stress in Europe and provide valuable insights for regional decision-makers and climate adaptation planning.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 19
    Publikationsdatum: 2024-01-31
    Beschreibung: The response of permafrost to submergence can vary between ice-rich late Pleistocene deposits and the thermokarst basins that thawed out during the Holocene. We hypothesize that inundated Alases offshore thaw faster than submerged Yedoma. To test this hypothesis, we estimated depths to the top of ice-bearing permafrost offshore of the Bykovsky Peninsula in northeast Siberia using electrical resistivity surveys. The surveys traversed submerged lagoon deposits, drained and refrozen Alas deposits, and undisturbed Yedoma from the coastline to 373 m offshore. While the permafrost degradation rates of the submerged Yedoma were in the range of similar sites, the submerged Alas permafrost degradation rates were up to 170% faster. Given the abundance of thermokarst basins and lakes along parts of the Arctic coastline, its effect on subsea permafrost degradation must be similarly prevalent. Remote sensing analyses suggest that 54% of lagoons wider than 500 m originated in thermokarst basins.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev , info:eu-repo/semantics/article
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 20
    Publikationsdatum: 2024-01-31
    Beschreibung: Permafrost thaw leads to thermokarst lake formation and talik growth tens of meters deep, enabling microbial decomposition of formerly frozen organic matter (OM). We analyzed two 17-m-long thermokarst lake sediment cores taken in Central Yakutia, Russia. One core was from an Alas lake in a Holocene thermokarst basin that underwent multiple lake generations, and the second core from a young Yedoma upland lake (formed ca. 70 years ago) whose sediments have thawed for the first time since deposition. This comparison provides a glance into OM fate in thawing Yedoma deposits. We analyzed total organic carbon (TOC) and dissolved organic carbon (DOC) content, n-alkanes concentrations, and bacterial and archaeal membrane markers. Furthermore, we conducted one-year-long incubations (4 °C, dark) and measured anaerobic carbon dioxide (CO2) and methane (CH4) production. The sediments from both cores contained little TOC (0.7±0.4 wt%), but DOC values were relatively high, with highest values in the frozen Yedoma lake sediments (1620 mg L-1). Cumulative GHG production after one year was highest in the Yedoma lake sediments (226±212 μg CO2-C gdw-1, 28±36 μg CH4-C gdw-1) and 3 and 1.5 times lower in the Alas lake sediments, respectively (75±76 μg CO2-C gdw-1, 19±29 μg CH4-C gdw-1). The highest CO2 production in the frozen Yedoma lake sediments likely results from decomposition of readily bioavailable OM, while highest CH4 production in the non-frozen top sediments of this core suggests that methanogenic communities established upon thaw. The lower GHG production in the non-frozen Alas lake sediments resulted from advanced OM decomposition during Holocene talik development. Furthermore, we found that drivers of CO2 and CH4 production differ following thaw. Our results suggest that GHG production from TOC-poor mineral deposits, which are widespread throughout the Arctic, can be substantial. Therefore, our novel data are relevant for vast ice-rich permafrost deposits vulnerable to thermokarst formation.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev , info:eu-repo/semantics/article
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 21
    facet.materialart.
    Unbekannt
    Wiley-Blackwell
    In:  EPIC3Permafrost and Periglacial Processes, Wiley-Blackwell, 32(1), pp. 59-75, ISSN: 1045-6740
    Publikationsdatum: 2024-01-31
    Beschreibung: Thermal erosion is a major mechanism of permafrost degradation, resulting in characteristic landforms. We inventory thermo-erosional valleys in ice-rich coastal lowlands adjacent to the Siberian Laptev Sea based on remote sensing, Geographic Information System (GIS), and field investigations for a first regional assessment of their spatial distribution and characteristics. Three study areas with similar geological (Yedoma Ice Complex) but diverse geomorphological conditions vary in valley areal extent, incision depth, and branching geometry. The most extensive valley networks are incised deeply (up to 35 m) into the broad inclined lowland around Mamontov Klyk. The flat, low-lying plain forming the Buor Khaya Peninsula is more degraded by thermokarst and characterized by long valleys of lower depth with short tributaries. Small, isolated Yedoma Ice Complex remnants in the Lena River Delta predominantly exhibit shorter but deep valleys. Based on these hydrographical network and topography assessments, we discuss geomorphological and hydrological connections to erosion processes. Relative catchment size along with regional slope interact with other Holocene relief-forming processes such as thermokarst and neotectonics. Our findings suggest that thermo-erosional valleys are prominent, hitherto overlooked permafrost degradation landforms that add to impacts on biogeochemical cycling, sediment transport, and hydrology in the degrading Siberian Yedoma Ice Complex.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev , info:eu-repo/semantics/article
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 22
    facet.materialart.
    Unbekannt
    Annual Reviews
    In:  EPIC3Annual Review of Marine Science, Annual Reviews, 16(1), pp. 513-536, ISSN: 1941-1405
    Publikationsdatum: 2024-01-31
    Beschreibung: 〈jats:p〉 For decades, multiple-driver/stressor research has examined interactions among drivers that will undergo large changes in the future: temperature, pH, nutrients, oxygen, pathogens, and more. However, the most commonly used experimental designs—present-versus-future and ANOVA—fail to contribute to general understanding or predictive power. Linking experimental design to process-based mathematical models would help us predict how ecosystems will behave in novel environmental conditions. We review a range of experimental designs and assess the best experimental path toward a predictive ecology. Full factorial response surface, fractional factorial, quadratic response surface, custom, space-filling, and especially optimal and sequential/adaptive designs can help us achieve more valuable scientific goals. Experiments using these designs are challenging to perform with long-lived organisms or at the community and ecosystem levels. But they remain our most promising path toward linking experiments and theory in multiple-driver research and making accurate, useful predictions. 〈/jats:p〉
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , peerRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 23
    Publikationsdatum: 2024-03-22
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , peerRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 24
    facet.materialart.
    Unbekannt
    Annual Reviews
    In:  EPIC3Annual Review of Marine Science, Annual Reviews, 15(1), pp. 509-538, ISSN: 1941-1405
    Publikationsdatum: 2024-05-10
    Beschreibung: The regular movements of waves and tides are obvious representations of the oceans’ rhythmicity. But the rhythms of marine life span across ecological niches and timescales, including short (in the range of hours) and long (in the range of days and months) periods. These rhythms regulate the physiology and behavior of individuals, as well as their interactions with each other and with the environment. This review highlights examples of rhythmicity in marine animals and algae that represent important groups of marine life across different habitats. The examples cover ecologically highly relevant species and a growing number of laboratory model systems that are used to disentangle key mechanistic principles. The review introduces fundamental concepts of chronobiology, such as the distinction between rhythmic and endogenous oscillator–driven processes. It also addresses the relevance of studying diverse rhythms and oscillators, as well as their interconnection, for making better predictions of how species will respond to environmental perturbations, including climate change. As the review aims to address scientists from the diverse fields of marine biology, ecology, and molecular chronobiology, all of which have their own scientific terms, we provide definitions of key terms throughout the article.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 25
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Journal of Climate, American Meteorological Society, 37(8), pp. 2505-2518, ISSN: 0894-8755
    Publikationsdatum: 2024-06-21
    Beschreibung: A fundamental statistic of climate variability is its spatiotemporal correlation function. Its complex structure can be concisely summarized by a frequency-dependent measure of the effective spatial degrees of freedom (ESDOF). Here we present, for the first time, frequency-dependent ESDOF estimates of global natural surface temperature variability from purely instrumental measurements, using the HadCRUT4 dataset (1850-2014). The approach is based on a newly developed method for estimating the frequency-dependent spatial correlation function from gappy data fields. Results reveal a multicomponent structure of the spatial correlation function, including a large-amplitude short-distance component (with weak time scale dependence) and a small-amplitude long-distance component (with increasing relative amplitude toward the longer time scales). Two frequency-dependent ESDOF measures are applied, each responding mainly to either of the two components. Both measures exhibit a significant ESDOF reduction from monthly to multidecadal time scales, implying an increase of the effective spatial scale of natural surface temperature fluctuations. Moreover, it is found that a good approximation to the global number of equally spaced samples needed to estimate the variance of global mean temperature is given, at any frequency, by the greater one of the two ESDOF measures, decreasing from ;130 at monthly to ;30 at multidecadal time scales. Finally, the multicomponent structure of the correlation function together with the detected ESDOF scaling properties indicate that the ESDOF reduction toward the longer time scales cannot be explained simply by diffusion acting on stochastically driven anomalies, as it might be suggested f rom simple stochastic-diffusive energy balance models.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 26
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Journal of Climate, American Meteorological Society, 34(18), pp. 7373-7388, ISSN: 0894-8755
    Publikationsdatum: 2024-06-21
    Beschreibung: Climate variability occurs over wide ranges of spatial and temporal scales. It exhibits a complex spatial covariance structure, which depends on geographic location (e.g., tropics vs extratropics) and also consists of a superposition of (i) components with gradually decaying positive correlation functions and (ii) teleconnections that often involve anticorrelations. In addition, there are indications that the spatial covariance structure depends on frequency. Thus, a comprehensive assessment of the spatiotemporal covariance structure of climate variability would require an extensive set of statistical diagnostics. Therefore, it is often desirable to characterize the covariance structure by a simple summarizing metric that is easy to compute from datasets. Such summarizing metrics are useful, for example, in the context of comparisons between climate models or between models and observations. Here we introduce a frequency-dependent version of a simple measure of the effective spatial degrees of freedom. The measure is based on the temporal variance of the global average of some climate variable, and its novel aspect consists in its frequency dependence. We also provide a clear geometric interpretation of the measure. Its easy applicability is demonstrated using near-surface temperature and precipitation fields obtained from a paleoclimate model simulation. This application reveals a distinct scaling behavior of the spatial degrees of freedom as a function of frequency, ranging from monthly to millennial scales.
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 27
    Publikationsdatum: 2024-05-29
    Beschreibung: NORP-SORP Workshop on Polar Fresh Water: Sources, Pathways and Impacts of Freshwater in Northern and Southern Polar Oceans and Seas (SPICE-UP) What: Up to 60 participants at a time and more than twice as many registrants in total from 20 nations and across experience levels met to discuss the current status of research on freshwater in both polar regions, future directions, and synergies between the Arctic and Southern Ocean research communities When: 19–21 September 2022 Where: Online
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , notRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 28
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Bulletin of the American Meteorological Society, American Meteorological Society, 104(9), pp. s1-s10, ISSN: 0003-0007
    Publikationsdatum: 2024-05-29
    Beschreibung: 〈jats:title〉Abstract〈/jats:title〉 〈jats:p〉—J. BLUNDEN, T. BOYER, AND E. BARTOW-GILLIES〈/jats:p〉 〈jats:p〉Earth’s global climate system is vast, complex, and intricately interrelated. Many areas are influenced by global-scale phenomena, including the “triple dip” La Niña conditions that prevailed in the eastern Pacific Ocean nearly continuously from mid-2020 through all of 2022; by regional phenomena such as the positive winter and summer North Atlantic Oscillation that impacted weather in parts the Northern Hemisphere and the negative Indian Ocean dipole that impacted weather in parts of the Southern Hemisphere; and by more localized systems such as high-pressure heat domes that caused extreme heat in different areas of the world. Underlying all these natural short-term variabilities are long-term climate trends due to continuous increases since the beginning of the Industrial Revolution in the atmospheric concentrations of Earth’s major greenhouse gases.〈/jats:p〉 〈jats:p〉In 2022, the annual global average carbon dioxide concentration in the atmosphere rose to 417.1±0.1 ppm, which is 50% greater than the pre-industrial level. Global mean tropospheric methane abundance was 165% higher than its pre-industrial level, and nitrous oxide was 24% higher. All three gases set new record-high atmospheric concentration levels in 2022.〈/jats:p〉 〈jats:p〉Sea-surface temperature patterns in the tropical Pacific characteristic of La Niña and attendant atmospheric patterns tend to mitigate atmospheric heat gain at the global scale, but the annual global surface temperature across land and oceans was still among the six highest in records dating as far back as the mid-1800s. It was the warmest La Niña year on record. Many areas observed record or near-record heat. Europe as a whole observed its second-warmest year on record, with sixteen individual countries observing record warmth at the national scale. Records were shattered across the continent during the summer months as heatwaves plagued the region. On 18 July, 104 stations in France broke their all-time records. One day later, England recorded a temperature of 40°C for the first time ever. China experienced its second-warmest year and warmest summer on record. In the Southern Hemisphere, the average temperature across New Zealand reached a record high for the second year in a row. While Australia’s annual temperature was slightly below the 1991–2020 average, Onslow Airport in Western Australia reached 50.7°C on 13 January, equaling Australia's highest temperature on record.〈/jats:p〉 〈jats:p〉While fewer in number and locations than record-high temperatures, record cold was also observed during the year. Southern Africa had its coldest August on record, with minimum temperatures as much as 5°C below normal over Angola, western Zambia, and northern Namibia. Cold outbreaks in the first half of December led to many record-low daily minimum temperature records in eastern Australia.〈/jats:p〉 〈jats:p〉The effects of rising temperatures and extreme heat were apparent across the Northern Hemisphere, where snow-cover extent by June 2022 was the third smallest in the 56-year record, and the seasonal duration of lake ice cover was the fourth shortest since 1980. More frequent and intense heatwaves contributed to the second-greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Glaciers in the Swiss Alps lost a record 6% of their volume. In South America, the combination of drought and heat left many central Andean glaciers snow free by mid-summer in early 2022; glacial ice has a much lower albedo than snow, leading to accelerated heating of the glacier. Across the global cryosphere, permafrost temperatures continued to reach record highs at many high-latitude and mountain locations.〈/jats:p〉 〈jats:p〉In the high northern latitudes, the annual surface-air temperature across the Arctic was the fifth highest in the 123-year record. The seasonal Arctic minimum sea-ice extent, typically reached in September, was the 11th-smallest in the 43-year record; however, the amount of multiyear ice—ice that survives at least one summer melt season—remaining in the Arctic continued to decline. Since 2012, the Arctic has been nearly devoid of ice more than four years old.〈/jats:p〉 〈jats:p〉In Antarctica, an unusually large amount of snow and ice fell over the continent in 2022 due to several landfalling atmospheric rivers, which contributed to the highest annual surface mass balance, 15% to 16% above the 1991–2020 normal, since the start of two reanalyses records dating to 1980. It was the second-warmest year on record for all five of the long-term staffed weather stations on the Antarctic Peninsula. In East Antarctica, a heatwave event led to a new all-time record-high temperature of −9.4°C—44°C above the March average—on 18 March at Dome C. This was followed by the collapse of the critically unstable Conger Ice Shelf. More than 100 daily low sea-ice extent and sea-ice area records were set in 2022, including two new all-time annual record lows in net sea-ice extent and area in February.〈/jats:p〉 〈jats:p〉Across the world’s oceans, global mean sea level was record high for the 11th consecutive year, reaching 101.2 mm above the 1993 average when satellite altimetry measurements began, an increase of 3.3±0.7 over 2021. Globally-averaged ocean heat content was also record high in 2022, while the global sea-surface temperature was the sixth highest on record, equal with 2018. Approximately 58% of the ocean surface experienced at least one marine heatwave in 2022. In the Bay of Plenty, New Zealand’s longest continuous marine heatwave was recorded.〈/jats:p〉 〈jats:p〉A total of 85 named tropical storms were observed during the Northern and Southern Hemisphere storm seasons, close to the 1991–2020 average of 87. There were three Category 5 tropical cyclones across the globe—two in the western North Pacific and one in the North Atlantic. This was the fewest Category 5 storms globally since 2017. Globally, the accumulated cyclone energy was the lowest since reliable records began in 1981. Regardless, some storms caused massive damage. In the North Atlantic, Hurricane Fiona became the most intense and most destructive tropical or post-tropical cyclone in Atlantic Canada’s history, while major Hurricane Ian killed more than 100 people and became the third costliest disaster in the United States, causing damage estimated at $113 billion U.S. dollars. In the South Indian Ocean, Tropical Cyclone Batsirai dropped 2044 mm of rain at Commerson Crater in Réunion. The storm also impacted Madagascar, where 121 fatalities were reported.〈/jats:p〉 〈jats:p〉As is typical, some areas around the world were notably dry in 2022 and some were notably wet. In August, record high areas of land across the globe (6.2%) were experiencing extreme drought. Overall, 29% of land experienced moderate or worse categories of drought during the year. The largest drought footprint in the contiguous United States since 2012 (63%) was observed in late October. The record-breaking megadrought of central Chile continued in its 13th consecutive year, and 80-year record-low river levels in northern Argentina and Paraguay disrupted fluvial transport. In China, the Yangtze River reached record-low values. Much of equatorial eastern Africa had five consecutive below-normal rainy seasons by the end of 2022, with some areas receiving record-low precipitation totals for the year. This ongoing 2.5-year drought is the most extensive and persistent drought event in decades, and led to crop failure, millions of livestock deaths, water scarcity, and inflated prices for staple food items.〈/jats:p〉 〈jats:p〉In South Asia, Pakistan received around three times its normal volume of monsoon precipitation in August, with some regions receiving up to eight times their expected monthly totals. Resulting floods affected over 30 million people, caused over 1700 fatalities, led to major crop and property losses, and was recorded as one of the world’s costliest natural disasters of all time. Near Rio de Janeiro, Brazil, Petrópolis received 530 mm in 24 hours on 15 February, about 2.5 times the monthly February average, leading to the worst disaster in the city since 1931 with over 230 fatalities.〈/jats:p〉 〈jats:p〉On 14–15 January, the Hunga Tonga-Hunga Ha'apai submarine volcano in the South Pacific erupted multiple times. The injection of water into the atmosphere was unprecedented in both magnitude—far exceeding any previous values in the 17-year satellite record—and altitude as it penetrated into the mesosphere. The amount of water injected into the stratosphere is estimated to be 146±5 Terragrams, or ∼10% of the total amount in the stratosphere. It may take several years for the water plume to dissipate, and it is currently unknown whether this eruption will have any long-term climate effect.〈/jats:p〉
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , peerRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 29
    facet.materialart.
    Unbekannt
    American Meteorological Society
    In:  EPIC3Bulletin of the American Meteorological Society, American Meteorological Society, 104(9), pp. s271-s321, ISSN: 0003-0007
    Publikationsdatum: 2024-05-29
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , peerRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 30
    Publikationsdatum: 2024-06-28
    Beschreibung: 〈jats:title〉Abstract〈/jats:title〉 〈jats:p〉This study quantifies the state-of-the-art in the rapidly growing field of seasonal Arctic sea ice prediction. A novel multi-model dataset of retrospective seasonal predictions of September Arctic sea ice is created and analyzed, consisting of community contributions from 17 statistical models and 17 dynamical models. Prediction skill is compared over the period 2001–2020 for predictions of Pan-Arctic sea ice extent (SIE), regional SIE, and local sea ice concentration (SIC) initialized on June 1, July 1, August 1, and September 1. This diverse set of statistical and dynamical models can individually predict linearly detrended Pan-Arctic SIE anomalies with skill, and a multi-model median prediction has correlation coefficients of 0.79, 0.86, 0.92, and 0.99 at these respective initialization times. Regional SIE predictions have similar skill to Pan-Arctic predictions in the Alaskan and Siberian regions, whereas regional skill is lower in the Canadian, Atlantic, and Central Arctic sectors. The skill of dynamical and statistical models is generally comparable for Pan-Arctic SIE, whereas dynamical models outperform their statistical counterparts for regional and local predictions. The prediction systems are found to provide the most value added relative to basic reference forecasts in the extreme SIE years of 1996, 2007, and 2012. SIE prediction errors do not show clear trends over time, suggesting that there has been minimal change in inherent sea ice predictability over the satellite era. Overall, this study demonstrates that there are bright prospects for skillful operational predictions of September sea ice at least three months in advance.〈/jats:p〉
    Repository-Name: EPIC Alfred Wegener Institut
    Materialart: Article , isiRev
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 31
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1967), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 32
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 33
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 34
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 35
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The paper traces the history of the Wild series of rectifiers, paying particular attention to the mechanical solutions of the Newton and Scheimpflug conditions.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 36
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 37
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: This paper gives a summary of the methods that have been used for independent model aerial triangulation. A modification of one of the methods is proposed and the paper concludes with a comparison of the independent model with the classical method of triangulation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 38
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 39
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 40
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 41
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The camera is a further development of an existing type with greatly improved photogrammetric performance so that the photography can be used with first-order plotting machines. A new lens provides minimal distortion, high resolution and greatly improved marginal illumination. An entirely new shutter provides high speeds and efficiency. Laboratory results and preliminary survey trials indicate image quality and location standards of the same order as established existing cameras.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 42
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Book reviews in this article:INTERNATIONAL YEAR BOOK OF CARTOGRAPHY (Vol. IV, 1964). Editor, Eduard Imhof.JUBILEE VOLUME DEDICATED TO WILLEM SCHERMERHORN ON HIS SEVENTIETH ANNIVERSARY: ESSAYS ON THE DEVELOPMENT OF PHOTOGRAMMETRY. Published by I.T.C., Delft.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 43
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 44
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 45
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The geologist's use of air photographs and the characteristics studied by photogeologists are briefly described. The influence of photographic factors such as scale, season, time of day, film type, processing, overlap and dimensional accuracy are considered from the geologist's viewpoint.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 46
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: This paper modifies the well-known formula that corrects x-parallaxes for tilt. It shows how we can make significant improvements in accuracy with a no more complicated formula, in which the effects of ground relief are completely removed; and how we can reduce the second-order errors due to lateral (w) tilts by very large factors in favourable cases.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 47
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 48
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 49
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1967), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Land systems are patterns of landscape recognised on aerial photographs and mapped to define areas of similar terrain with a similar environment. Breaks of slope often form the major boundaries both between and within land systems. They can be usefully mapped from aerial photographs even if their significance can only be deduced after ground investigation. Many of the characteristics of land systems can be appreciated from aerial photographs and measurements made on the photographs can improve their quantitative description.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 50
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1967), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: A method of slotted templet triangulation is described in which the authors have used photographs printed on a stable base as the templets. The advantages, disadvantages and possibilities of the method are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 51
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The paper gives, for a large number of cases, numerical errors due to using approximate, first-order, formulae for correcting x-parallaxes for tilt. The figures show that the errors are considerably smaller than might be expected. It is also shown that the root mean square of the four tilts of a pair of pictures is a reliable measure from which the effect of tilt on heights can be estimated with some confidence.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 52
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 53
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 54
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 55
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Research work is being undertaken by the Department of Orthodontics at Addenbrooke's Hospital, Cambridge, which involves studying the growth of children's faces in three dimensions. In evaluating the morphology of soft tissues, the advantages offered by photogrammetry have been recognised and this paper describes how the technique has been put into practice at the hospital where a stereometric instrument, equally suitable for use as a camera or as a projection plotter, has been constructed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 56
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 57
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 58
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The history of the Argentine-Chile frontier is briefly reviewed. The paper then describes the photogrammetric and land-surveying work that formed part of the recent settlement of a section of the frontier, that was referred to the British Government for arbitration.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 59
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 60
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Topics of immediate practical interest formed the basis of the Address. Particular emphasis was placed upon problems of point transfer, pre-marking of ground control points, aerial triangulation by observation of independent models, and the status of photogrammetric operators.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 61
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The article describes a method of strip aerial triangulation using the Wild B8 plotter. The principal feature of the method is the transfer of exterior orientation of a camera by measurement of outer orientation parallel to successive airbases.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 62
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 63
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1968), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 64
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1967), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: After a brief review of the history of the orthophoto mapping process and its methods, the paper describes the automatic production of orthophotographs in the BS-Stereomat. Technical details, especially of the electronics of the instrument, are given. The range of applications of an orthophoto is discussed, as well as the method's limitations.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 65
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Equipment manufactured in connexion with the special applications of photogrammetry has developed from very early designs, often with remarkably few changes. The first section of the paper traces this evolution up to the present time.Architectural photogrammetry has been, since Meydenbauer, one of the most important of these special applications and the second part describes some recent work of this type in England and Jordan.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 66
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 6 (1969), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The problem of incorporating airborne auxiliary data into an aerial triangulation block adjustment is considered. The conclusion is reached that this problem can be most readily solved by the use of a fully rigorous adjustment method. The first order adjustment equations for all types of airborne auxiliary control are developed and the method of incorporating these equations into the block solution is demonstrated. The general computing problems of the aerial triangulation block adjustment are briefly discussed and a method outlined for the incorporation of tie strips, at any angle across the block, into the adjustment without unduly increasing the storage requirements for the solution. The problem of correctly weighting the different types of available data is discussed. The paper concludes with a demonstration of the improved accuracy possible if precise aerial triangulation data are combined with apparently crude absolute airborne data.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 67
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: The author explains one of the chief problems, the composition of a survey aircraft navigation system, facing Commission I of the International Society for Photogrammetry. The tasks to be accomplished by such a system are outlined, and some of the alternative equipment available to carry out the various aspects of this work are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 68
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: It is well known that there exists a “danger cylinder” for space resection, analogous to the “danger circle” in the plane, on which the resection is unstable. This paper shows how the existence of this surface may be detected and draws attention to the way in which the instability differs from that in the plane.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 69
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: A successful attempt has been made to produce design plans of large chemical plant using photogrammetric techniques, and involving the development and modification of cameras and plotting equipment. Photogrammetry has provided a solution to a problem which could not easily be solved by direct methods.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 70
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Book reviews in this article:PROCEEDINGS OF THE SECOND NATIONAL CONFERENCE OF SOUTH AFRICAN SURVEYORS, FEBRUARY 1964. Edited by G. H. Menzies et al.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 71
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Four authors review the activities of the seven Commissions of the I.S.P. at the Xth International Congress, Lisbon, 1964.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 72
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 73
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 74
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 75
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1967), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: This paper discusses a simple method of computing independent strips under certain reasonable approximations. It is shown that, if the method is regarded as if it were computation by polynomials, the order of the polynomial is decided by the nature of the control provided and not by the number of controlled models. This conclusion should throw some light on the vexed (and perennial) problem of the choice of orders for polynomials.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 76
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: An attempt is made to review the factors affecting the use of colour photography in photogrammetry and photo-interpretation. Examples of current practice and results of comparative tests are quoted, as well as the advantages and deficiencies of the various materials available.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 77
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: During the summer of 1965, colour, false colour, infra-red and panchromatic photography was flown of the Breidamerkur Glacier area in south-east Iceland. Subsequent comparative interpretation studies of the film types have indicated that colour photography is superior for the interpretation of glacierized† areas. This is attributed to brightness qualities and a continuous colour tone range, which, in this instance, closely matched visual representation of ground objects.The false colour film, due to the striking tonal qualities of vegetation and moisture, is considered best for studies involving the delimitation of these features. Panchromatic film appears to be satisfactory for general interpretation work, particularly where the utmost in definition is called for. The infra-red film, because of the dark tones produced by gravels and the subsequent high contrasts between ice and gravel debris on the ice surface, is considered a poor choice for the interpretation of glacierized areas.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 78
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 79
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: This paper gives convenient formulae for numerical relative orientation for use with instruments in which the Y-parallax may be accurately measured.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 80
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1966), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 81
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: Rather than rely on laboratory calibration, test fields have been established in Sweden to enable photography from a tower or aircraft, and so simulate as nearly as possible actual operational conditions. Repeated experiments, followed by analysis of photography, and the application of statistical tests, have allowed the geometrical quality of the aerial photograph to be assessed, and systematic and irregular errors to be distinguished.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 82
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Notizen: It does not seem to be widely recognised that the solution of the space resection problem from measurements made on a single photograph of three ground control points is not unique. There are, in general, four solutions, so that either the camera orientation must be approximately known (as is the case for near vertical photography) or extra control must be used to discriminate between these solutions. The iterative solution commonly used will only yield one solution, which will be correct if the photography is nearly vertical, but which is liable to be wrong in the general case. An explicit solution is therefore preferred since all solutions may be examined in the light of such extra control as is available. This paper gives a method for such a solution and shows how the discrimination should be used. The paper goes on to derive a method of adjusting the result to redundant control by least squares.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 83
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 84
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @photogrammetric record 5 (1965), S. 0 
    ISSN: 1477-9730
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 85
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. In cultures of Trypanosoma conorhini the authors have detected “cyst-like bodies” (CLBs) that, in the initial phase, have the appearance of 2 or more overgrown crithidiae fused together; after disorganization of the internal structure of the parent flagellates and division of their organelles, new crithidiae are formed within the CLB. The wall of the CLB consists of an irregularly thick layer of cytoplasm surrounded by the periplast of the parent flagellates and a true cystic membrane is not evident. The daughter crithidiae eventually escape from the CLB leaving the periplast and other residues of the parent flagellates. It is suggested that this represents a method of reproduction entirely different from binary or multiple fission, that is probably common to other trypanosomes of the Section STERCORARIA, and that it may provide for genetic exchange even if it is not a true sexual process.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 86
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. During conjugation of Kahlia the micronuclei divide 3 times before synkaryon formation and 2 times thereafter. The 1st division is heterotypic, as in other ciliates, in that it is characterized by the parachute stage. Following this stage, 24 to 26 bivalents and 4 to 8 univalents appear in the micronuclear area. When the bivalents move to organize the metaphase plate, the univalents lag behind and fail to reach the equatorial region at the same time. Due to this irregular behavior of the univalents there is no distinct metaphase in the first meiotic division. A few meiotic irregularities including the breakdown of the spindle apparatus have been observed. During the breakdown of the spindle apparatus the chromosomes fuse into irregular bodies which resemble the chromosome aggregates observed during the somatic divisions. Generally 1, and rarely more, of the products of the 1st division enter the 2nd division. The spindles of this division are oriented parallel to the long axis of the cell, and 1 of the daughter nuclei reaches the partition membrane separating the conjugants. This nucleus alone undergoes the 3rd division, resulting in the formation of gametic nuclei. Reciprocal exchange and fusion of the gametic nuclei result in the synkaryon formation. The synkaryon divides twice in rapid succession resulting in 4 daughter nuclei; 1 of them degenerates and 2 condense and become functional micronuclei. The chromosomes of the remaining daughter nucleus resemble in size and number the bivalents of the 1st meiotic division. They become polytenic and then reproduce to give rise to the polyploid macronucleus. The development of the macronucleus has been traced from a single diploid set of chromosomes and no evidence has been found for the formation of genetic “subnuclei.” During the early stages of the development of the macronuclear anlage, somatic pairing forces keep the homologs together, while in the later stages these forces cease to exert influence. While these changes are in progress the old macronucleus; breaks up into small irregular polymorphic bodies which are scattered throughout in the cytoplasm. The exconjugants usually encyst and the cysts are not favorable for detailed cytologic study.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 87
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. In young first generation schizonts of E. bovis, the nuclei appeared to have a random distribution. In calves killed 8 days after inoculation some of the schizonts had the nuclei arranged in a single layer at the periphery, with a few infoldings of this layer into the interior. In further development, such ingrowths of the nuclear layer resulted in the formation of compartments of varying size. In schizonts of calves killed 12 days after inoculation spherical or ellipsoidal bodies (blastophores), about 5–20 μ in diameter with a single peripheral layer of nuclei were formed. Merozoites developed as radial outgrowths from the blastophores, leaving residual bodies of variable size, which later disappeared. The response of the host cell to the presence of the schizont was characterized by marked growth of both the nucleus and cytoplasm. The nucleolus became greatly enlarged, and the chromatin was distributed in relatively fine granules. In the host cell cytoplasm, 2 concentric layers were observed; the inner was more dense than the outer. After growth of the schizont was completed its host cell was stretched into a thin covering layer about 1 μ thick. In some schizonts, the host cell disintegrated, and the schizont was then invaded by eosinophils, macrophages and other cells, which eventually destroyed the merozoites.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 88
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Blood smears from 133 Rio Grande wild turkeys Meleagridis gallopavo intermedia live-trapped in the Welder Wildlife Refuge in south Texas, were examined for blood parasites. All of the 63 immature turkeys and 63% of the 70 adult turkeys were infected with Haemoproteus meleagridis. The infections were light, half the cases having less than 5 infected cells per 10,000 red blood cells. Infection with H. meleagridis caused significant enlargement of the host RBC. Other parasites specifically searched for but not found were Leucocytozoon, Trypanosoma, Plasmodium and microfilariae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 89
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. The fine structure of the tomite stage of Hyalophysa chattoni was examined with particular attention to its kinetal apparatus.The pellicle, thick and dense compared with that of other ciliates, is formed of three layers. The inner layer is composed of short fibrils oriented perpendicular to the surface.The cytoplasm around the oral passage and beneath falciform field 8 is crowded with dense inclusion bodies of unknown function. Dorsal to the oral passage is the rosette, a disc-shaped organelle subdivided by septa in the form of incomplete radii about a central chamber containing a tuft of cilia. The septa are composed of 3 membranes enclosing a fine layer of cytoplasm. At their inner ends 20 mμ fibers run dorsally and ventrally. Dense clumps of fibrous material line the luminal surface of the septa.Rows of fusiform trichocysts parallel the kineties. The trichocysts are composed of a finely periodic, moderately electron-dense material surrounded by 20 mμ fibrils oriented along the long axis of the trichocyst. Between and below the kinetosomes and the rows of trichocysts are electron-dense vesicles 300 mμ in diameter and bounded by a loose membrane. The large “trichocysts,” the “gros trichocystes” of Chatton and Lwoff, whose appearance heralds the beginnings of trichocystogenesis, prove to be canaliculi opening to the surface.Four separate ciliary membrane systems—the oral ciliature (XYZ), falciform field 8, falciform field 9, and the ogival field—are located on the ventral surface of the tomite. Each differs from the others and from the somatic kineties in the fibrillar organization around its kinetosomes.In the somatic kineties the kinetodesmos is a dense, periodic fiber which is formed of stacks of up to 18 subfibers, each arising from the base of a kinetosome. The kinetosomes are short (300 mμ) and contain dense central granules. In some kineties, alternating between the kinetosomes, are elliptical kinetosome-like structures which do not bear cilia and perhaps provide a reservoir of kinetosomes for future growth of the kinety.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 90
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. The life cycle of the true slime mold Physarum polycephalum includes 2 vegetative stages: the multinucleate coenocytic plasmodium and the uninucleate amoeba. A clone of amoebae established from a single spore does not normally yield plasmodia. Plasmodia are formed when amoebae from particular clones are mixed; thus plasmodium formation is said to be controlled by a ‘mating-type’ system.Previous work by the author with a sample of P. polycephalum derived from a single source revealed that 2 mating types were present and were determined by a pair of alleles at 1 locus. The present paper reveals the presence of 2 more mating types in a sample of P. polycephalum derived from a different source and provides evidence that these are determined by 2 alleles at the same locus as the other 2.Evidence for the presence of other inherited factors affecting plasmodium formation, the mode of action of these factors and possible explanations for the occurrence of plasmodia in single-spore cultures are also discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 91
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Transection and regeneration of Blepharisma intermedium initiate complex macronuclear activity and micronuclear division. Reversible condensation of the macronucleus is achieved by contraction which involves primary and secondary coiling. Primary coiling, evident in vegetative cells, is enhanced by pronounced constriction of the macronuclear extremities during regeneration. Secondary coiling is restricted to the period of contraction and is initiated at the ends of the mauonucleus. Condensation terminates the coiling processes and gives rise to an amorphous structure. Re-elongation of the macronucleus is not followed immediately by coiling. Micronuclear division begins early in regeneration, but the peak of visible activity is not reached until the 3rd through 5th hours.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 92
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Lipids in aging cultures of Tetrakymena pyriformis were extracted at various times after inoculation, purified, and weighed or chromatographed on thin layers of silica gel. The total cellular lipid increased throughout logarithmic and early stationary phases but decreased sharply after 72 hr. The amount of one lipid class, probably the triglycerides, followed the same trends. It may be a cellular reserve.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 93
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Rearing of cockroaches without sporozoan parasites of the Malpighian tubules permitted the 1st experimental infections reported for these organisms as well as study of the intracellular early stages of infection. Infectivity tests show that the route of invasion is peroral rather than transovarian; that fresh spores obtained from either the Malpighian tubules or the hindgut are infective; that fresh spores held in aqueous suspension for 36 hr are not infective; that all ages and both sexes of cockroaches are susceptible, although older cockroaches are more readily infected experimentally; that a single peroral dose of a few hundred spores is sufficient to produce infection; that the earliest signs of progressive infection in the Malpighian tubules appear 15 days after ingestion of spores; and that the infection, spread mainly by schizogony, is well established by 23 days. Spores are acid-fast. The PAS-positive spore membrane is not dissolved by 20-min treatment with hot KOH, but tests for chitin were inconclusive. The life history of the parasite is described. “Encapsulation” of the parasite has been observed. Electron microscope studies, the first reported for the class Haplosporea, show similarities of the cytoplasmic structure of this haplosporidian with that of some members of the sporozoan class Telosporea, though no specialized structures were seen. Finding of intracellular stages together with failure of interspecific infection attempts suggest that the microorganism should be placed in the genus Nephridiophaga Ivanic, 1937 with the specific name blattellae Crawley, 1905.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 94
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. A centrifugation procedure for removing Tetrahymena from mass cultures is described. This method offers the following advantages: (a) inexpensive apparatus, (b) the short period of time required for harvesting large numbers of cells, (c) lack of cellular damage, (d) the ability to obtain proven dilution with regard to the culture fluid, (e) nearly quantitative recovery of the cells, and (f) the ease of assembling and disassembling the apparatus for cleaning.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 95
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Monocercomonas molae from the hindgut of the sunfish Mola mola is described. The host was taken from southern California coastal waters in October, 1964. The body of the flagellate is 8.0 × 10.7 microns. A single basal granule complex gives rise to 4 flagella, one of which is recurrent. The axostyle is relatively stout, with argentophilic granules, and possesses a periaxostylar ring. The capitulum of the axostyle continues into the sickle-shaped pelta, and the parabasal body is rod-shaped or lobed and roughly triangular in cross-section.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 96
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. The complete life history of a homothallic, dioecious strain of Volvox aureus was studied in axenic culture. Asexual reproduction occurs by repeated division of specialized reproductive cells (gonidia), inversion of the resultant mass of cells to form daughter colonies, and subsequent morphologic differentiation of new gonidia in these daughters. Male colonies lack gonidia; however, the posterior 2/3 of the cells in a colony function as male initials each of which enlarges, divides, and undergoes rudimentary inversion to form a packet of 32 biflagellate sperm. Evidence was presented for the homology of eggs and undivided gonidia. The penetration of young vegetative colonies by sperm and the subsequent formation of apparent zygotes in these colonies was described and figured. Zygote germination, including division and inversion of the germling, was described; the cytological nature of the zygote divisions was not determined.A substance, MIS, in filtrates of sexual cultures induced differentiation of male colonies; a bioassay for it was perfected. Bioassay colonies show a differential susceptibility to male induction by MIS which is a function of the particular stage of development; colonies 48 hr after release from parentals are optimally susceptible. MIS was reasonably stable to heat, non-dialyzable, and Sephadex gel filtration indicated a molecular weight 〉 200,000. MIS activity is destroyed by trypsin and pronase but is unaffected by chymotrypsin. MIS was successfully concentrated ∼37-fold by the Carbowax method. The patterns of differentiation in other species of Volvox are described and possibilities discussed for studies of cellular differentiation in the genus as a whole.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 97
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Haemogregarina faiyumensis n. sp., a parasite of toads, Bufo regularis, in Faiyuni Province, Egypt, U.A.R., is described. In a survey of 689 toads from various localities in Cairo, Giza and Faiyurn provinces, only 3 out of 13 toads from Kom O Shim near Faiyum were infected. This species, known only by blood forms (most probably gametocytes) of two different staining reactions, is 13-17 μ long and 4-5 μ wide, with an average of 15.5 × 4.5 μ. The nucleus is typically subcircular and 3-5 × 3–5 μ, with an average of 4.5 × 3.9 μ.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 98
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Haemogregarina boueti França, 1910, was found to be the commonest blood parasite in the common toad, Bufo regularis Reuss, in Egypt. The rate of infection was about 30% (of 689 toads examined).In properly fixed blood films, the parasites were almost exclusively intraerythrocytic. Most characteristic was the encapsulated “elongate” form averaging 22.3 by 6 μ with a more-or-less central nucleus and a pointed, slightly bent, posterior end. Infected red cells were conspicuously hypertrophied and their nuclei were markedly displaced and frequently broken into 2-4 parts.Young and growing blood forms as well as two types of hepatic schizonts are described for the first time.Schizonts of the first type develop in hepatic cells, are 28–30 μ in diameter and produce numerous elongate oval merozoites about 8 × 2.2 μ radially arranged around a residual body about 10 μ in diameter.Schizonts of the second type start their growth in erythrocytes but later complete their development as free bodies in the liver sinusoids. When mature, they are 32–35 μ in diameter and produce a larger number of thin merozoites about 8 × 1.5 μ, surrounding a larger residual body about 19 μ in diameter.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 99
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Haemogregarina pestanae França, 1910, is apparently rare in Egypt, having been found in 1 toad Bufo regularis Reuss out of 689 examined. Capsulated capped, young thin, and young and advanced broad forms were present in the peripheral blood. Schizogony occurred in the liver. Two types of schizonts were present—macroschizonts producing 150 or more elongate oval merozoites surrounding a large residual body, and microschizonts producing 60 or less banana-shaped merozoites often radiating from a small, eccentric residual body.Merozoites of the first type developed into a large broad form representing early schizonts of the second type. The latter developed into thin young intraerythrocytic forms and apparently later into encapsulated capped gametocytes. H. pestanae, H. aegyptia and H. tunisiensis all occur in toads (Bufo regularis for the first two, and B. mauritanicus for the third), and produce characteristic encapsulated looped gametocytes in peripheral blood. The capsules contain dark-staining material condensed into a single well-developed cap in H. aegyptia and 1 or 2 much smaller caps in H. pestanae; this material is scattered regularly around the parasite in H. tunisiensis. The capsule of H. pestanae is more or less cylindrical along most of its length, more slender and slightly shorter than the regularly oval capsule of H. tunisiensis or the spindle- or egg-shaped capsule of H. aegyptia.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 100
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: SYNOPSIS. Spathidium spathula irradiated with 0 to 55 kr of × rays showed one or more of the following kinds of behavior: (1) Death of an undivided cell (primary death); (2) death of a descendant of an irradiated cell (secondary death); (3) permanent injury including one or more of the following: low daily division rate, excessive macronuclear enlargement, total loss of micronuclei, cytostome replication, heavy pigmentation, and decreased motility; (4) temporary division retardation for 1 to 2 days followed by apparent complete recovery; and (5) no apparent injury. The first 3 kinds of behavior increased with increasing dosage from 15 to 25 to 55 kr. At 6 kr only the last 2 categories were observed. The LD50 for 8 days was 46 kr for both primary and secondary death, or 60 kr for primary death alone.Micronuclear number varied greatly following irradiation in lines showing either permanent or temporary injury. Two different responses occurred: (1) The micronuclear number averaged about twice the normal number of 20 with a large range (0 to 360) 1 day after exposure. The number gradually decreased during the next 2 days; (2) some cells lost all micronuclei following irradiation, the incidence increasing with dose. At 55 kr complete loss of micronuclei occurred in 96% of the surviving lines.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...