Contributions of GPS occultations to Antarctica ice sheet mass balance studies
Antarctica is the coldest, stormiest and the most remote continent on Earth. Nearly 75% of the world's fresh water is trapped in the Antarctic ice sheets, which could significantly raise the global sea level if the ice sheets would melt. The continental ice sheet mass balance budget remains one...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_231929 2023-05-15T13:52:13+02:00 Contributions of GPS occultations to Antarctica ice sheet mass balance studies Ge, S. Shum, C. Wickert, J. 2002 https://gfzpublic.gfz-potsdam.de/pubman/item/item_231929 unknown https://gfzpublic.gfz-potsdam.de/pubman/item/item_231929 1st International Workshop on Occultations for Probing Atmosphere and Climate (Graz 2002) 550 - Earth sciences info:eu-repo/semantics/conferenceObject 2002 ftgfzpotsdam 2022-09-14T05:55:48Z Antarctica is the coldest, stormiest and the most remote continent on Earth. Nearly 75% of the world's fresh water is trapped in the Antarctic ice sheets, which could significantly raise the global sea level if the ice sheets would melt. The continental ice sheet mass balance budget remains one of the largest uncertainties in the understanding of the causes of global sea level rise. Advanced gravity mapping satellite missions, such as CHAMP, GRACE and GOCE, are anticipated to provide significant measurements in the form of temporal gravity field to quantify ice sheet mass balance and its contribution to global sea level rise. To fully exploit of the accuracy of GRACE, equivalent of less than several mm-level measurement accuracy of ground water movement over a spatial scale of 200 km monthly at satellite altitude, the knowledge of the surface pressure fields over Antarctica is needed at an accuracy of sub-mbar (rms). The current operational meteorological analyses from ECMWF (6-hourly), and NCEP (3-hourly), both with 100 km spatial resolutions, are inadequate both in accuracy and resolution for an adequate correction of the GRACE measurements to extract ice sheet mass balance signals. In this paper, we study the use of spaceborne GPS occultation measurements from CHAMP, SAC-C and GRACE to potentially provide an improved atmospheric pressure field for GRACE gravity corrections. The retrieved atmospheric measurements are studied based on assumption that water vapor is scarce over the interior of the Antarctic continent, to compute pressure profiles. Improved pressure fields could also be available by employing 4DVAR assimilation techniques using bending angles and refractivities derived from GPS occultations. In this paper, results will be presented in comparing operational meteorological analysis models (NCEP and ECMWF) as well as their validation using Automatic Weather Stations (AWS) data in Antarctica. It is also demonstrated that GPS occultation technique could be a substantially valuable data source to ... Conference Object Antarc* Antarctic Antarctica Ice Sheet GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Antarctic The Antarctic |
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Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
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ftgfzpotsdam |
language |
unknown |
topic |
550 - Earth sciences |
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550 - Earth sciences Ge, S. Shum, C. Wickert, J. Contributions of GPS occultations to Antarctica ice sheet mass balance studies |
topic_facet |
550 - Earth sciences |
description |
Antarctica is the coldest, stormiest and the most remote continent on Earth. Nearly 75% of the world's fresh water is trapped in the Antarctic ice sheets, which could significantly raise the global sea level if the ice sheets would melt. The continental ice sheet mass balance budget remains one of the largest uncertainties in the understanding of the causes of global sea level rise. Advanced gravity mapping satellite missions, such as CHAMP, GRACE and GOCE, are anticipated to provide significant measurements in the form of temporal gravity field to quantify ice sheet mass balance and its contribution to global sea level rise. To fully exploit of the accuracy of GRACE, equivalent of less than several mm-level measurement accuracy of ground water movement over a spatial scale of 200 km monthly at satellite altitude, the knowledge of the surface pressure fields over Antarctica is needed at an accuracy of sub-mbar (rms). The current operational meteorological analyses from ECMWF (6-hourly), and NCEP (3-hourly), both with 100 km spatial resolutions, are inadequate both in accuracy and resolution for an adequate correction of the GRACE measurements to extract ice sheet mass balance signals. In this paper, we study the use of spaceborne GPS occultation measurements from CHAMP, SAC-C and GRACE to potentially provide an improved atmospheric pressure field for GRACE gravity corrections. The retrieved atmospheric measurements are studied based on assumption that water vapor is scarce over the interior of the Antarctic continent, to compute pressure profiles. Improved pressure fields could also be available by employing 4DVAR assimilation techniques using bending angles and refractivities derived from GPS occultations. In this paper, results will be presented in comparing operational meteorological analysis models (NCEP and ECMWF) as well as their validation using Automatic Weather Stations (AWS) data in Antarctica. It is also demonstrated that GPS occultation technique could be a substantially valuable data source to ... |
format |
Conference Object |
author |
Ge, S. Shum, C. Wickert, J. |
author_facet |
Ge, S. Shum, C. Wickert, J. |
author_sort |
Ge, S. |
title |
Contributions of GPS occultations to Antarctica ice sheet mass balance studies |
title_short |
Contributions of GPS occultations to Antarctica ice sheet mass balance studies |
title_full |
Contributions of GPS occultations to Antarctica ice sheet mass balance studies |
title_fullStr |
Contributions of GPS occultations to Antarctica ice sheet mass balance studies |
title_full_unstemmed |
Contributions of GPS occultations to Antarctica ice sheet mass balance studies |
title_sort |
contributions of gps occultations to antarctica ice sheet mass balance studies |
publishDate |
2002 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_231929 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_source |
1st International Workshop on Occultations for Probing Atmosphere and Climate (Graz 2002) |
op_relation |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_231929 |
_version_ |
1766256481994276864 |