Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates
We present regional-scale mass balances for 25 drainage basins of the Antarctic Ice Sheet (AIS) from satellite observations of the Gravity and Climate Experiment (GRACE) for time period January 2003 to September 2012. Satellite gravimetry estimates of the AIS mass balance are strongly influenced by...
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ftcopernicus:oai:publications.copernicus.org:tc16610 2023-05-15T13:24:13+02:00 Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates Sasgen, I. Konrad, H. Ivins, E. R. Broeke, M. R. Bamber, J. L. Martinec, Z. Klemann, V. 2018-09-27 application/pdf https://doi.org/10.5194/tc-7-1499-2013 https://tc.copernicus.org/articles/7/1499/2013/ eng eng doi:10.5194/tc-7-1499-2013 https://tc.copernicus.org/articles/7/1499/2013/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-7-1499-2013 2020-07-20T16:25:21Z We present regional-scale mass balances for 25 drainage basins of the Antarctic Ice Sheet (AIS) from satellite observations of the Gravity and Climate Experiment (GRACE) for time period January 2003 to September 2012. Satellite gravimetry estimates of the AIS mass balance are strongly influenced by mass movement in the Earth interior caused by ice advance and retreat during the last glacial cycle. Here, we develop an improved glacial-isostatic adjustment (GIA) estimate for Antarctica using newly available GPS uplift rates, allowing us to more accurately separate GIA-induced trends in the GRACE gravity fields from those caused by current imbalances of the AIS. Our revised GIA estimate is considerably lower than previous predictions, yielding an estimate of apparent mass change of 53 ± 18 Gt yr −1 . Therefore, our AIS mass balance of −114 ± 23 Gt yr −1 is less negative than previous GRACE estimates. The northern Antarctic Peninsula and the Amundsen Sea sector exhibit the largest mass loss (−26 ± 3 Gt yr −1 and −127 ± 7 Gt yr −1 , respectively). In contrast, East Antarctica exhibits a slightly positive mass balance (26 ± 13 Gt yr −1 ), which is, however, mostly the consequence of compensating mass anomalies in Dronning Maud and Enderby Land (positive) and Wilkes and George V Land (negative) due to interannual accumulation variations. In total, 6% of the area constitutes about half the AIS imbalance, contributing 151 ± 7 Gt yr −1 (ca. 0.4 mm yr −1 ) to global mean sea-level change. Most of this imbalance is caused by ice-dynamic speed-up expected to prevail in the near future. Text Amundsen Sea Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Enderby Land George V Land Ice Sheet Copernicus Publications: E-Journals Amundsen Sea Antarctic Antarctic Peninsula East Antarctica George V Land ENVELOPE(148.000,148.000,-68.500,-68.500) The Antarctic The Cryosphere 7 5 1499 1512 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
We present regional-scale mass balances for 25 drainage basins of the Antarctic Ice Sheet (AIS) from satellite observations of the Gravity and Climate Experiment (GRACE) for time period January 2003 to September 2012. Satellite gravimetry estimates of the AIS mass balance are strongly influenced by mass movement in the Earth interior caused by ice advance and retreat during the last glacial cycle. Here, we develop an improved glacial-isostatic adjustment (GIA) estimate for Antarctica using newly available GPS uplift rates, allowing us to more accurately separate GIA-induced trends in the GRACE gravity fields from those caused by current imbalances of the AIS. Our revised GIA estimate is considerably lower than previous predictions, yielding an estimate of apparent mass change of 53 ± 18 Gt yr −1 . Therefore, our AIS mass balance of −114 ± 23 Gt yr −1 is less negative than previous GRACE estimates. The northern Antarctic Peninsula and the Amundsen Sea sector exhibit the largest mass loss (−26 ± 3 Gt yr −1 and −127 ± 7 Gt yr −1 , respectively). In contrast, East Antarctica exhibits a slightly positive mass balance (26 ± 13 Gt yr −1 ), which is, however, mostly the consequence of compensating mass anomalies in Dronning Maud and Enderby Land (positive) and Wilkes and George V Land (negative) due to interannual accumulation variations. In total, 6% of the area constitutes about half the AIS imbalance, contributing 151 ± 7 Gt yr −1 (ca. 0.4 mm yr −1 ) to global mean sea-level change. Most of this imbalance is caused by ice-dynamic speed-up expected to prevail in the near future. |
format |
Text |
author |
Sasgen, I. Konrad, H. Ivins, E. R. Broeke, M. R. Bamber, J. L. Martinec, Z. Klemann, V. |
spellingShingle |
Sasgen, I. Konrad, H. Ivins, E. R. Broeke, M. R. Bamber, J. L. Martinec, Z. Klemann, V. Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates |
author_facet |
Sasgen, I. Konrad, H. Ivins, E. R. Broeke, M. R. Bamber, J. L. Martinec, Z. Klemann, V. |
author_sort |
Sasgen, I. |
title |
Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates |
title_short |
Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates |
title_full |
Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates |
title_fullStr |
Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates |
title_full_unstemmed |
Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates |
title_sort |
antarctic ice-mass balance 2003 to 2012: regional reanalysis of grace satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on gps uplift rates |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-7-1499-2013 https://tc.copernicus.org/articles/7/1499/2013/ |
long_lat |
ENVELOPE(148.000,148.000,-68.500,-68.500) |
geographic |
Amundsen Sea Antarctic Antarctic Peninsula East Antarctica George V Land The Antarctic |
geographic_facet |
Amundsen Sea Antarctic Antarctic Peninsula East Antarctica George V Land The Antarctic |
genre |
Amundsen Sea Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Enderby Land George V Land Ice Sheet |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Enderby Land George V Land Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-7-1499-2013 https://tc.copernicus.org/articles/7/1499/2013/ |
op_doi |
https://doi.org/10.5194/tc-7-1499-2013 |
container_title |
The Cryosphere |
container_volume |
7 |
container_issue |
5 |
container_start_page |
1499 |
op_container_end_page |
1512 |
_version_ |
1766378131496632320 |