气候变化领域集成服务门户(CCPortal): Atmospheric extremes caused high oceanward sea surface slope triggering the biggest calving event in more than 50 years at the Amery Ice Shelf

CCPortal

DOI	10.5194/tc-15-2147-2021
	Atmospheric extremes caused high oceanward sea surface slope triggering the biggest calving event in more than 50 years at the Amery Ice Shelf
	Francis D.; Mattingly K.S.; Lhermitte S.; Temimi M.; Heil P.
发表日期	2021
ISSN	19940416
起始页码	2147
结束页码	2165
卷号	15 期号:5
英文摘要	Ice shelf instability is one of the main sources of uncertainty in Antarctica's contribution to future sea level rise. Calving events play a crucial role in ice shelf weakening but remain unpredictable, and their governing processes are still poorly understood. In this study, we analyze the unexpected September 2019 calving event from the Amery Ice Shelf, the largest since 1963 and which occurred almost a decade earlier than expected, to better understand the role of the atmosphere in calving.We find that atmospheric extremes provided a deterministic role in this event. A series of anomalously deep and stationary explosive twin polar cyclones over the Cooperation and Davis seas generated tides and winddriven ocean slope, leading to fracture amplification along the pre-existing rift and ultimately calving of the massive iceberg. The calving was triggered by high oceanward sea surface slopes produced by the storms. The observed recordanomalous atmospheric conditions were promoted by blocking ridges and Antarctic-wide anomalous poleward transport of heat and moisture. Blocking highs helped in (i) directing moist and warm air masses towards the ice shelf and (ii) maintaining the observed extreme cyclones stationary at the front of the ice shelf for several days. Accumulation of cold air over the ice sheet, due to the blocking highs, led to the formation of an intense cold high pressure over the ice sheet, which helped fuel sustained anomalously deep cyclones via increased baroclinicity. Our results stress the importance of atmospheric extremes in ice shelf dynamics via tides and sea surface slope and its need to be accounted for when considering Antarctic ice shelf variability and contribution to sea level, especially given that more of these extremes are predicted under a warmer climate. © Author(s) 2021.
英文关键词	air-sea interaction; atmosphere-ocean coupling; ice shelf; iceberg calving; sea surface; Antarctic Ice Sheet; Antarctica
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202308
作者单位	Environmental and Geophysical Sciences (ENGEOS) Lab, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08901-8554, United States; Department of Geoscience and Remote Sensing, Delft University of Technology, Mekelweg 5, Delft, 2628 CD, Netherlands; Department of Civil, Environmental and Ocean Engineering (CEOE), Stevens Institute of Technology, Hoboken, NJ 07030, United States; Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, TAS 7001, Australia
推荐引用方式 GB/T 7714	Francis D.,Mattingly K.S.,Lhermitte S.,et al. Atmospheric extremes caused high oceanward sea surface slope triggering the biggest calving event in more than 50 years at the Amery Ice Shelf[J],2021,15(5).
APA	Francis D.,Mattingly K.S.,Lhermitte S.,Temimi M.,&Heil P..(2021).Atmospheric extremes caused high oceanward sea surface slope triggering the biggest calving event in more than 50 years at the Amery Ice Shelf.Cryosphere,15(5).
MLA	Francis D.,et al."Atmospheric extremes caused high oceanward sea surface slope triggering the biggest calving event in more than 50 years at the Amery Ice Shelf".Cryosphere 15.5(2021).