Observations and Impact of Atmospheric River-Driven Extreme Precipitation over Thwaites Glacier
Abstract
Atmospheric rivers (ARs) impacting Antarctica travel southward from the midlatitudes, carrying long, narrow bands of warm and moist air. They contribute up to 20% of the total precipitation over the Antarctic Ice Sheet per year, and account for the highest precipitation rates (24 mm w.e. per hour and above) in MERRA-2 reanalysis (1980-2016). Here, we examine a major AR event over Thwaites Glacier in West Antarctica that occurred in February 2020. By combining in-situ snow height observations on Thwaites ice shelf, and MERRA-2 and ERA5 reanalyses over Thwaites Glacier, we identify the atmospheric patterns associated with the AR event and its impacts on snow accumulation. We then compare the spatial signature of this event with regional AR flavors (defined by precipitation type and intensity, wind speed, and temperature) along the Amundsen Sea coastline to develop a comprehensive picture of AR-driven extreme precipitation in West Antarctica. Finally, we examine the relationship between the temporal and spatial patterns of AR events and large-scale modes of atmospheric variability to recognize how these extreme events and their consequent impacts on accumulation and surface melt will influence future Thwaites Glacier mass balance.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC053...03M
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHERE;
- 0762 Mass balance;
- CRYOSPHERE;
- 0774 Dynamics;
- CRYOSPHERE;
- 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERAL