Climatology and surface impacts of atmospheric rivers on West Antarctica

Atmospheric rivers (ARs) transport large amounts of moisture from the mid- to high-latitudes and they are a primary driver of the most extreme snowfall events, along with surface melting, in Antarctica. In this study, we characterize the climatology and surface impacts of ARs on West Antarctica, foc...

Full description

Bibliographic Details
Published in:The Cryosphere
Main Authors: Maclennan, Michelle L., Lenaerts, Jan T. M., Shields, Christine A., Hoffman, Andrew O., Wever, Nander, Thompson-Munson, Megan, Winters, Andrew C., Pettit, Erin C., Scambos, Theodore A., Wille, Jonathan D.
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2023
Subjects:
article
Verlagsveröffentlichung
Amundsen Sea
Antarctic
Antarctic Peninsula
Byrd
Marie Byrd Land
Merra
The Antarctic
West Antarctica
Antarc*
Antarctica
Ice Shelf
The Cryosphere
Online Access:https://doi.org/10.5194/tc-17-865-2023
https://noa.gwlb.de/receive/cop_mods_00065097
https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00063718/tc-17-865-2023.pdf
https://tc.copernicus.org/articles/17/865/2023/tc-17-865-2023.pdf
Description
Summary:Atmospheric rivers (ARs) transport large amounts of moisture from the mid- to high-latitudes and they are a primary driver of the most extreme snowfall events, along with surface melting, in Antarctica. In this study, we characterize the climatology and surface impacts of ARs on West Antarctica, focusing on the Amundsen Sea Embayment and Marie Byrd Land. First, we develop a climatology of ARs in this region, using an Antarctic-specific AR detection tool combined with the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) and the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) atmospheric reanalyses. We find that while ARs are infrequent (occurring 3 % of the time), they cause intense precipitation in short periods of time and account for 11 % of the annual surface accumulation. They are driven by the coupling of a blocking high over the Antarctic Peninsula with a low-pressure system known as the Amundsen Sea Low. Next, we use observations from automatic weather stations on Thwaites Eastern Ice Shelf with the firn model SNOWPACK and interferometric reflectometry (IR) to examine a case study of three ARs that made landfall in rapid succession from 2 to 8 February 2020, known as an AR family event. While accumulation dominates the surface impacts of the event on Thwaites Eastern Ice Shelf (> 100 kg m−2 or millimeters water equivalent), we find small amounts of surface melt as well (< 5 kg m−2). The results presented here enable us to quantify the past impacts of ARs on West Antarctica's surface mass balance (SMB) and characterize their interannual variability and trends, enabling a better assessment of future AR-driven changes in the SMB.

Similar Items