Atmospheric triggers of the Brunt Ice Shelf calving in February 2021
The calving of Antarctic ice shelves remains unpredictable to date due to a lack of understanding of the role of the different climatic components in such events. In this presentation, the role of atmospheric forcing in the calving of the Brunt Ice Shelf (BIS) in the Weddell Sea sector of Antarctica...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5016109 2023-10-09T21:45:54+02:00 Atmospheric triggers of the Brunt Ice Shelf calving in February 2021 Francis, D. Fonseca, R. Mattingly, K. Marsh, O. Lhermitte, S. Cherif, C. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016109 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0338 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016109 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-0338 2023-09-17T23:43:20Z The calving of Antarctic ice shelves remains unpredictable to date due to a lack of understanding of the role of the different climatic components in such events. In this presentation, the role of atmospheric forcing in the calving of the Brunt Ice Shelf (BIS) in the Weddell Sea sector of Antarctica in February 2021 is discussed using a combination of observational and reanalysis data. The occurrence of a series of extreme cyclones around the time of the calving induced an oceanward sea-surface slope of >0.08° leading to the calving along a pre-existing rift. The severe storms were sustained by the development of a pressure dipole on both sides of the BIS associated with a La Niña event and the positive phase of the Southern Annular Mode. Poleward advection of warmer and more moist low-latitude air over the BIS area just before the calving was also observed in association with atmospheric rivers accompanying the cyclones. Immediately after the calving, strong offshore winds continued and promoted the drift of the newly-formed iceberg A-74 in the Weddell Sea at a speed of up to 700 m/day. The findings of this work highlight the contribution of local atmospheric conditions to ice-shelf dynamics. The link to the larger scale circulation patterns indicates that both need to be accounted for in the projections of Antarctic ice shelf evolution. Conference Object Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Shelf Ice Shelves Iceberg* Weddell Sea GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Antarctic Brunt Ice Shelf ENVELOPE(-22.500,-22.500,-74.750,-74.750) Weddell Weddell Sea |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
The calving of Antarctic ice shelves remains unpredictable to date due to a lack of understanding of the role of the different climatic components in such events. In this presentation, the role of atmospheric forcing in the calving of the Brunt Ice Shelf (BIS) in the Weddell Sea sector of Antarctica in February 2021 is discussed using a combination of observational and reanalysis data. The occurrence of a series of extreme cyclones around the time of the calving induced an oceanward sea-surface slope of >0.08° leading to the calving along a pre-existing rift. The severe storms were sustained by the development of a pressure dipole on both sides of the BIS associated with a La Niña event and the positive phase of the Southern Annular Mode. Poleward advection of warmer and more moist low-latitude air over the BIS area just before the calving was also observed in association with atmospheric rivers accompanying the cyclones. Immediately after the calving, strong offshore winds continued and promoted the drift of the newly-formed iceberg A-74 in the Weddell Sea at a speed of up to 700 m/day. The findings of this work highlight the contribution of local atmospheric conditions to ice-shelf dynamics. The link to the larger scale circulation patterns indicates that both need to be accounted for in the projections of Antarctic ice shelf evolution. |
format |
Conference Object |
author |
Francis, D. Fonseca, R. Mattingly, K. Marsh, O. Lhermitte, S. Cherif, C. |
spellingShingle |
Francis, D. Fonseca, R. Mattingly, K. Marsh, O. Lhermitte, S. Cherif, C. Atmospheric triggers of the Brunt Ice Shelf calving in February 2021 |
author_facet |
Francis, D. Fonseca, R. Mattingly, K. Marsh, O. Lhermitte, S. Cherif, C. |
author_sort |
Francis, D. |
title |
Atmospheric triggers of the Brunt Ice Shelf calving in February 2021 |
title_short |
Atmospheric triggers of the Brunt Ice Shelf calving in February 2021 |
title_full |
Atmospheric triggers of the Brunt Ice Shelf calving in February 2021 |
title_fullStr |
Atmospheric triggers of the Brunt Ice Shelf calving in February 2021 |
title_full_unstemmed |
Atmospheric triggers of the Brunt Ice Shelf calving in February 2021 |
title_sort |
atmospheric triggers of the brunt ice shelf calving in february 2021 |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016109 |
long_lat |
ENVELOPE(-22.500,-22.500,-74.750,-74.750) |
geographic |
Antarctic Brunt Ice Shelf Weddell Weddell Sea |
geographic_facet |
Antarctic Brunt Ice Shelf Weddell Weddell Sea |
genre |
Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Shelf Ice Shelves Iceberg* Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Brunt Ice Shelf Ice Shelf Ice Shelves Iceberg* Weddell Sea |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0338 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016109 |
op_doi |
https://doi.org/10.57757/IUGG23-0338 |
_version_ |
1779321567428214784 |