Assessing the vulnerability of fast ice in McMurdo Sound, Antarctica to winter storms ...

• Main Authors: Leonard, Greg, Richter, Maren, Smith, Inga, Turner, Kate, Whittaker, Maddy
• Format: Conference Object
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Ross Sea; McMurdo Sound; Antarc*; Antarctica; Sea ice
• Online Access: https://dx.doi.org/10.57757/iugg23-2805; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019091

<!--!introduction!--> 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 ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...