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
    Decomposing Barotropic Transport Variability in a High-Resolution Model of the North Atlantic Ocean (2021)
    Details
    Publication Date: 2021-10-12
    Description: A method using a linear shallow water model is presented for decomposing the temporal variability of the barotropic stream function in a high-resolution ocean model. The method is based on the vertically averaged momentum equations and is applied to the time series of annual mean stream function from the model configuration VIKING20 for the northern North Atlantic. An important result is the role played by the nonlinear advection terms in VIKING20 for driving transport. The method is illustrated by examining how the Gulf Stream transport in the recirculation region responds to the winter North Atlantic Oscillation (NAO). While no statistically significant response is found in the year overlapping with the winter NAO index, there is a tendency for the Gulf Stream transport to increase as the NAO becomes more positive. This becomes significant in lead years 1 and 2 when the mean flow advection and eddy momentum flux contributions, associated with nonlinear momentum advection, dominate. Only after 2 years, does the potential energy term, associated with the density field, start to play a role and it is only after 5 years that the transport dependence on the NAO ceases to be significant. It is also shown that the potential energy contribution to the transport stream function has significant memory of up to 5 years in the Labrador and Irminger Seas. However, it is only around the northern rim of these seas that VIKING20 and the transport reconstruction exhibit similar memory. This is due to masking by the mean flow advection and eddy momentum flux contributions.
    Keywords: 551.46 ; North Atlantic ; transport variability ; high-resolution model
    Language: English
    Type: map
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    CITATION GEO-LEO
  • 2
    facet.materialart.
    Unknown
    International Space Station (ISS) Accommodation of a Single US Assured Crew Return Vehicle (ACRV) (1997)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The following report was generated to give the International Space Station (ISS) Program some additional insight into the operations and issues associated with accommodating a single U.S. developed Assured Crew Return Vehicle (ACRV). During the generation of this report, changes in both the ISS and ACRV programs were factored into the analysis with the realization that most of the work performed will eventually need to be repeated once the two programs become more integrated. No significant issues associated with the ISS accommodating the ACRV were uncovered. Kinematic analysis of ACRV installation showed that there are viable methods of using Shuttle and Station robotic manipulators. Separation analysis demonstrated that the ACRV departure path clears the Station structure for all likely contingency scenarios. The payload bay packaging analysis identified trades that can be made between payload bay location, Shuttle Remote Manipulator System (SRMS) reach and eventual designs of de-orbit stages and docking adapters.
    Keywords: Launch Vehicles and Space Vehicles
    Type: NASA/TM-97-206272 , NAS 1.15:206272 , L-17683
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Air-Cooled Design of a Temperature-Swing Adsorption Compressor for Closed-Loop Air Revitalization Systems (2004)
    In:  Other Sources
    Details
    Publication Date: 2019-07-18
    Description: The air revitalization system of the International Space Station (ISS) operates in an open loop mode and relies on the resupply of oxygen and other consumables from earth for the life support of astronauts. A compressor is required for delivering the carbon dioxide from a removal assembly to a reduction unit to recover oxygen and thereby closing the air-loop. We have a developed a temperature-swing adsorption compressor (TSAC) for performing these tasks that is energy efficient, quiet, and has no rapidly moving parts. This paper discusses the mechanical design and the results of thermal model validation tests of a TSAC that uses air as the cooling medium.
    Keywords: Mechanical Engineering
    Type: 34rd International Conference on Environmental Systems Meeting; Jul 19, 2004 - Jul 22, 2004; Colorado Springs, CO; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Development and Testing of a Temperature-swing Adsorption Compressor for Carbon Dioxide in Closed-loop Air Revitalization Systems (2005)
    In:  Other Sources
    Details
    Publication Date: 2019-07-18
    Description: The air revitalization system of the International Space Station (ISS) operates in an open loop mode and relies on the resupply of oxygen and other consumables from earth for the life support of astronauts. A compressor is required for delivering the carbon dioxide from a removal assembly to a reduction unit to recover oxygen and thereby dosing the air-loop. We have developed a temperature-swing adsorption compressor (TSAC) that is energy efficient, quiet, and has no rapidly moving parts for performing these tasks. The TSAC is a solid-state compressor that has the capability to remove CO2 from a low- pressure source, and subsequently store, compress, and deliver at a higher pressure as required by a processor. The TSAC is an ideal interface device for CO2 removal and reduction units in the air revitalization loop of a spacecraft for oxygen recovery. This paper discusses the design and testing of a TSAC for carbon dioxide that has application in the ISS and future spacecraft for closing the air revitalization loop.
    Keywords: Mechanical Engineering
    Type: 35th International Conference on Environmental Systems; Jul 11, 2005 - Jul 14, 2005; Rome; Italy
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Shear-wave velocity structure of the shallow sediments in the Bohai Sea from an ocean-bottom-seismometer survey (2016)
    Society of Exploration Geophysicists
    In:  Geophysics, 81 (3). ID25-ID36.
    Details
    Publication Date: 2019-02-01
    Description: To investigate the seismic velocity structure of the shallow sediments in the Bohai Sea of China, we conducted a shearwave velocity inversion of the surface-wave dispersion data from a survey of 12 ocean-bottom seismometers (OBSs) and 377 shots of a 9000 in3 air gun. With OBS station spacing of approximately 5 km and air-gun shot spacing of approximately 190 m, high-quality Scholte-wave data were recorded by the OBSs within 0.4–5 km offset. We retrieved the Scholtewave phase-velocity dispersion for the fundamental mode and first overtone in the frequency band of 0.9–3.0 Hz with the phase-shift method and inverted for the shear-wave velocity structure of the shallow sediments with a damped iterative least-squares algorithm. Pseudo-2D shear-wave velocity profiles with a depth of approximately 400 m revealed coherent features of relatively weak lateral velocity variation. We also estimated the uncertainty in shear-wave velocity structure based on the pseudo-2D profiles from six trial inversions with different initial models, which suggested a velocity uncertainty less than 30 m∕s for most parts of the 2D profiles. The layered structure with little lateral variation may be attributable to the continuous sedimentary environment in the Cenozoic sedimentary basin of the Bohai Bay basin. The shear-wave velocity of 200–300 m∕s in the top 100 m of the Bohai seafloor may provide important information for offshore site response studies in earthquake engineering. Furthermore, the very low shear-wave velocity structure (150–600 m∕s) down to 400 m depth could produce a significant traveltime delay of approximately 1 s in the shear-wave arrivals, which needs to be considered to avoid serious bias in shear-wave traveltime tomographic models.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 6
    facet.materialart.
    Unknown
    Decomposition of the Mean Barotropic Transport in a High-Resolution Model of the North Atlantic Ocean (2018)
    In:  [Poster] In: EGU General Assembly 2018, 08.-13.04.2018, Vienna, Austria .
    Details
    Publication Date: 2018-11-19
    Description: We show how a barotropic shallow water model can be used to decompose the mean barotropic transport from a high-resolution ocean model based on the vertically averaged momentum equations. We apply the method to a high-resolution model of the North Atlantic for which the local vorticity budget is both noisy and dominated by small spatial scales. The shallow water model acts as an effective filter and clearly reveals the transport driven by each term. The potential energy (joint effect of baroclinicity and bottom relief) term is the most important for driving transport, including in the northwest corner, while mean flow advection is important for driving transport along f/H contours around the Labrador Sea continental slope. Both the eddy momentum flux and the mean flow advection terms drive significant transport along the pathway of the Gulf Stream and the North Atlantic Current
    Type: Conference or Workshop Item , NonPeerReviewed
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 7
    facet.materialart.
    Unknown
    Decomposition of the mean barotropic transport in a high-resolution model of the North Atlantic Ocean (2017)
    AGU (American Geophysical Union) | Wiley
    Details
    Publication Date: 2023-01-31
    Description: We show how a barotropic shallow water model can be used to decompose the mean barotropic transport from a high-resolution ocean model based on the vertically-averaged momentum equations. We apply the method to a high resolution model of the North Atlantic for which the local vorticity budget is both noisy and dominated by small spatial scales. The shallow water model acts as an effective filter and clearly reveals the transport driven by each term. The potential energy (JEBAR) term is the most important for driving transport, including in the northwest corner, while mean flow advection is important for driving transport along f/H contours around the Labrador Sea continental slope. Both the eddy momentum flux and the mean flow advection terms drive significant transport along the pathway of the Gulf Stream and the North Atlantic Current.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
  • 8
    facet.materialart.
    Unknown
    Decomposing barotropic transport variability in a high‐resolution model of the North Atlantic Ocean (2020)
    AGU (American Geophysical Union) | Wiley
    Details
    Publication Date: 2023-02-08
    Description: A method using a linear shallow water model is presented for decomposing the temporal variability of the barotropic streamfunction in a high‐resolution ocean model. The method is based in the vertically‐averaged momentum equations and is applied to the time series of annual mean streamfunction from the model configuration VIKING20 for the northern North Atlantic. An important result is the role played by the nonlinear advection terms in VIKING20 for driving transport. The method is illustrated by examining how the Gulf Stream transport in the recirculation region responds to the winter North Atlantic Oscillation (NAO). While no statistically significant response is found in the year overlapping with the winter NAO index, there is a tendency for the Gulf Stream transport to increase as the NAO becomes more positive. This becomes significant in lead years 1 and 2 when the mean flow advection (MFA) and eddy momentum flux (EMF) contributions, associated with nonlinear momentum advection, dominate. Only after 2 years, does the potential energy (PE) term, associated with the density field, start to play a role and it is only after 5 years that the transport dependence on the NAO ceases to be significant. It is also shown that the PE contribution to the transport streamfunction has significant memory of up to 5 years in the Labrador and Irminger Seas. However, it is only around the northern rim of these seas that VIKING20 and the transport reconstruction exhibit similar memory. This is due to masking by the MFA and EMF contributions.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OCEANREP)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...