ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Experimental design for three interrelated marine ice sheet and ocean model intercomparison projects: MISMIP v. 3 (MISMIP +), ISOMIP v. 2 (ISOMIP +) and MISOMIP v. 1 (MISOMIP1) (2016)
    In:  Geoscientific Model Development
    Details
    Publication Date: 2022-03-21
    Description: Coupled ice sheet–ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of marine ice sheets and tidewater glaciers, from process studies to future projections of ice mass loss and sea level rise. The Marine Ice Sheet–Ocean Model Intercomparison Project (MISOMIP) is a community effort aimed at designing and coordinating a series of model intercomparison projects (MIPs) for model evaluation in idealized setups, model verification based on observations, and future projections for key regions of the West Antarctic Ice Sheet (WAIS). Here we describe computational experiments constituting three interrelated MIPs for marine ice sheet models and regional ocean circulation models incorporating ice shelf cavities. These consist of ice sheet experiments under the Marine Ice Sheet MIP third phase (MISMIP+), ocean experiments under the Ice Shelf-Ocean MIP second phase (ISOMIP+) and coupled ice sheet–ocean experiments under the MISOMIP first phase (MISOMIP1). All three MIPs use a shared domain with idealized bedrock topography and forcing, allowing the coupled simulations (MISOMIP1) to be compared directly to the individual component simulations (MISMIP+ and ISOMIP+). The experiments, which have qualitative similarities to Pine Island Glacier Ice Shelf and the adjacent region of the Amundsen Sea, are designed to explore the effects of changes in ocean conditions, specifically the temperature at depth, on basal melting and ice dynamics. In future work, differences between model results will form the basis for the evaluation of the participating models.
    Type: info:eu-repo/semantics/article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    CITATION PIK
  • 2
    facet.materialart.
    Unknown
    An Intensive Observation of Calving at Helheim Glacier, East Greenland (2016)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Calving of glacial ice into the ocean from the Greenland Ice Sheet is an important component of global sea-level rise. The calving process itself is relatively poorly observed, understood, and modeled; as such, it represents a bottleneck in improving future global sea-level estimates in climate models. We organized a pilot project to observe the calving process at Helheim Glacier in east Greenland in an effort to better understand it. During an intensive one-week survey, we deployed a suite of instrumentation, including a terrestrial radar interferometer, global positioning system (GPS) receivers, seismometers, tsunameters, and an automated weather station. We were fortunate to capture a calving process and to measure various glaciological, oceanographic, and atmospheric parameters before, during, and after the event. One outcome of our observations is evidence that the calving process actually consists of a number of discrete events, spread out over time, in this instance over at least two days. This time span has implications for models of the process. Realistic projections of future global sea level will depend on an accurate parametrization of calving, and we argue that more sustained observations will be required to reach this objective.
    Keywords: Oceanography
    Type: GSFC-E-DAA-TN40840 , Oceanography (ISSN 1042-8275); 29; 4; 46-61
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Bathymetry of Southeast Greenland From Oceans Melting Greenland (OMG) Data (2019)
    AGU (American Geophysical Union) | Wiley
    In:  Geophysical Research Letters, 46 (20). pp. 11197-11205.
    Details
    Publication Date: 2022-01-31
    Description: Southeast Greenland has been a major participant in the ice sheet mass loss over the last several decades. Interpreting the evolution of glacier fronts requires information about their depth below sea level and ocean thermal forcing, which are incompletely known in the region. Here, we combine airborne gravity and multibeam echo sounding data from the National Aeronautics and Space Administration's Oceans Melting Greenland (OMG) mission with ocean probe and fishing boat depth data to reconstruct the bathymetry extending from the glacier margins to the edges of the continental shelf. We perform a three‐dimensional inversion of the gravity data over water and merge the solution with a mass conservation reconstruction of bed topography over land. In contrast with other parts of Greenland, we find few deep troughs connecting the glaciers to the sources of warm Atlantic Water, amidst a relatively uniform, shallow (350 m) continental shelf. The deep channels include the Kangerlugssuaq, Sermilik, Gyldenløve, and Tingmiarmiut Troughs.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 4
    facet.materialart.
    Unknown
    Atmospheric carbon dioxide concentrations before 2.2 billion years ago (1995)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: The composition of the Earth's early atmosphere is a subject of continuing debate. In particular, it has been suggested that elevated concentrations of atmospheric carbon dioxide would have been necessary to maintain normal surface temperatures in the face of lower solar luminosity in early Earth history. Fossil weathering profiles, known as palaeosols, have provided semi-quantitative constraints on atmospheric oxygen partial pressure (pO2) before 2.2 Gyr ago. Here we use the same well studied palaeosols to constrain atmospheric pCO2 between 2.75 and 2.2 Gyr ago. The observation that iron lost from the tops of these profiles was reprecipitated lower down as iron silicate minerals, rather than as iron carbonate, indicates that atmospheric pCO2 must have been less than 10(-1.4) atm--about 100 times today's level of 360 p.p.m., and at least five times lower than that required in one-dimensional climate models to compensate for lower solar luminosity at 2.75 Gyr. Our results suggest that either the Earth's early climate was much more sensitive to increases in pCO2 than has been thought, or that one or more greenhouse gases other than CO2 contributed significantly to the atmosphere's radiative balance during the late Archaean and early Proterozoic eons.
    Keywords: Meteorology and Climatology
    Type: Nature (ISSN 0028-0836); Volume 378; 6557; 603-5
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Development of a microminiature sorption cooler (1997)
    In:  CASI
    Details
    Publication Date: 2004-12-03
    Description: The development of a microcooler for operations below 80 K, for low temperature electronic devices requiring small cooling powers of the order of 10 mW is described. A sorption compressor combined with Joule-Thomson (JT) expansion was selected for miniaturization. The advantage of the system is considered to be its absence of moving parts, with the exception of the check valves. This facilitates the scaling down of the system, minimizes interferences and contributes to a long lifetime. The requirements for small scale cooling of low temperature electronics are listed. The sorption compressor and the JT expansion are described. A parameter study is reviewed together with the scaling of the sorption compressor.
    Keywords: Engineering (General)
    Type: Proceedings of the 6th European Symposium on Space Environmental Control Systems, volume 2; Volume 2; 489-496; ESA-SP-400-Vol-2
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    A first-order theory for the rotational motion of a triaxial rigid body orbiting an oblate primary. (1969)
    In:  Other Sources
    Details
    Publication Date: 2011-08-12
    Description: Gravitational and magnetic torque effect on rotational motion of triaxial rigid body in regressing orbit about oblate primary mass
    Keywords: SPACE SCIENCES
    Type: ; ERA, TP NO. 661, (
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Surface-plasmon cross coupling in molecular fluorescence near a corrugated thin metal film (1968)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Surface plasmons on opposite sides of a thin metal film can cross couple in the presence of a surface corrugation, or grating. The observation of this cross-coupling phenomenon as a radiative-decay mechanism for molecules near a corrugated thin metal film is reported.
    Keywords: ATOMIC AND MOLECULAR PHYSICS
    Type: Physical Review Letters (ISSN 0031-9007); 56; 2838-284
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    X-33 Environmental Impact Statement: A Fast Track Approach (1999)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The purpose of this presentation is to discuss the developmental approach to the Environmental Impact Statement regarding the X-33 vehicle.
    Keywords: Environment Pollution
    Type: Third Aerospace Environmental Technology Conference; 43-53; NASA/CP-1999-209258
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    The HST Key Project on the Extragalactic Distance Scale VI. The Cepheids in NGC925 (1996)
    In:  Other Sources
    Details
    Publication Date: 2018-06-08
    Description: We report the detection of Cepheid Variable stars in the barred spiral galaxy NGC925, using the Hubble Space Telescope (HST) Wide Field and Planetary Camera 2 (WFPC2). Twelve V (F555W), four I (F814W) and three B (F439W) epochs of cosmic ray split observations were obtained. Eighty Cepheids were discovered, with periods from 6 to +-80 days. Light curves of the Cepheids are presented, and their corresponding period-luminosity diagrams are discussed.
    Keywords: Astronomy
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Reliability analysis of single crystal NiAl turbine blades (1995)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: As part of a co-operative agreement with General Electric Aircraft Engines (GEAE), NASA LeRC is modifying and validating the Ceramic Analysis and Reliability Evaluation of Structures algorithm for use in design of components made of high strength NiAl based intermetallic materials. NiAl single crystal alloys are being actively investigated by GEAE as a replacement for Ni-based single crystal superalloys for use in high pressure turbine blades and vanes. The driving force for this research lies in the numerous property advantages offered by NiAl alloys over their superalloy counterparts. These include a reduction of density by as much as a third without significantly sacrificing strength, higher melting point, greater thermal conductivity, better oxidation resistance, and a better response to thermal barrier coatings. The current drawback to high strength NiAl single crystals is their limited ductility. Consequently, significant efforts including the work agreement with GEAE are underway to develop testing and design methodologies for these materials. The approach to validation and component analysis involves the following steps: determination of the statistical nature and source of fracture in a high strength, NiAl single crystal turbine blade material; measurement of the failure strength envelope of the material; coding of statistically based reliability models; verification of the code and model; and modeling of turbine blades and vanes for rig testing.
    Keywords: METALLIC MATERIALS
    Type: NASA-TM-111138 , NAS 1.15:111138 , NIPS-95-06099
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...