Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms
McMurdo Sound sea ice can generally be partitioned into two regimes: (1) a stable fast-ice cover, forming south of approximately 77.6 ∘S around March – April and then breaking out the following January – February, and (2) a more dynamic region north of 77.6 ∘S that the McMurdo Sound and Ross Sea pol...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5019091 2023-09-26T15:10:34+02:00 Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms Leonard, G. Richter, M. Smith, I. Turner, K. Whittaker, M. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019091 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2805 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019091 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-2805 2023-08-27T23:42:01Z McMurdo Sound sea ice can generally be partitioned into two regimes: (1) a stable fast-ice cover, forming south of approximately 77.6 ∘S around March – April and then breaking out the following January – February, and (2) a more dynamic region north of 77.6 ∘S that the McMurdo Sound and Ross Sea polynyas regularly impact. In 2019, a stable fast-ice cover formed unusually late due to repeated break-out events. Here we analyse the 2019 sea-ice conditions and relate them to a modified storm index (MSI), a proxy for southerly wind events. We determined there is a strong correlation between the timing of break-out events and several unusually large MSI events and our key finding is that an increase in the frequency of intense winter storms in 2019 resulted in a delayed formation of a stable fast-ice cover. Further, recent observations (post 2019) demonstrate that fast-ice conditions in 2019 were not unique and suggest that the fate of fast ice in the sound may be a symptom of some larger change. Winter fast-ice dynamics in the sound appear to be largely driven by synoptic events as there are no identifiable trends in monthly-averages of atmospheric drivers (e.g. air temperature, mean sea level pressure and wind speed and direction) of fast-ice breakout in the period 1985 – 2022. This study offers new insights into the mechanisms behind individual break-out events and is one of a few case studies that investigate the stability of a fast-ice cover in winter. Conference Object Antarc* Antarctica McMurdo Sound Ross Sea Sea ice GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) McMurdo Sound Ross Sea |
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Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
McMurdo Sound sea ice can generally be partitioned into two regimes: (1) a stable fast-ice cover, forming south of approximately 77.6 ∘S around March – April and then breaking out the following January – February, and (2) a more dynamic region north of 77.6 ∘S that the McMurdo Sound and Ross Sea polynyas regularly impact. In 2019, a stable fast-ice cover formed unusually late due to repeated break-out events. Here we analyse the 2019 sea-ice conditions and relate them to a modified storm index (MSI), a proxy for southerly wind events. We determined there is a strong correlation between the timing of break-out events and several unusually large MSI events and our key finding is that an increase in the frequency of intense winter storms in 2019 resulted in a delayed formation of a stable fast-ice cover. Further, recent observations (post 2019) demonstrate that fast-ice conditions in 2019 were not unique and suggest that the fate of fast ice in the sound may be a symptom of some larger change. Winter fast-ice dynamics in the sound appear to be largely driven by synoptic events as there are no identifiable trends in monthly-averages of atmospheric drivers (e.g. air temperature, mean sea level pressure and wind speed and direction) of fast-ice breakout in the period 1985 – 2022. This study offers new insights into the mechanisms behind individual break-out events and is one of a few case studies that investigate the stability of a fast-ice cover in winter. |
format |
Conference Object |
author |
Leonard, G. Richter, M. Smith, I. Turner, K. Whittaker, M. |
spellingShingle |
Leonard, G. Richter, M. Smith, I. Turner, K. Whittaker, M. Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms |
author_facet |
Leonard, G. Richter, M. Smith, I. Turner, K. Whittaker, M. |
author_sort |
Leonard, G. |
title |
Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms |
title_short |
Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms |
title_full |
Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms |
title_fullStr |
Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms |
title_full_unstemmed |
Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms |
title_sort |
assessing the vulnerability of fast ice in mcmurdo sound, antarctica to winter storms |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019091 |
geographic |
McMurdo Sound Ross Sea |
geographic_facet |
McMurdo Sound Ross Sea |
genre |
Antarc* Antarctica McMurdo Sound Ross Sea Sea ice |
genre_facet |
Antarc* Antarctica McMurdo Sound Ross Sea Sea ice |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2805 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019091 |
op_doi |
https://doi.org/10.57757/IUGG23-2805 |
_version_ |
1778145441366409216 |