Large-Scale Atmospheric Drivers of Snowfall over Thwaites Glacier, Antarctica

• Main Author: Maclennan, Michelle L
• Format: Text
• Language: unknown
• Published: CU Scholar 2019
• Subjects: Thwaites Glacier; snowfall; Amundsen Sea Low; Climate; Glaciology; Oceanography and Atmospheric Sciences and Meteorology; West Antarctica; Amundsen Sea; Merra; Antarc*; Antarctica
• Online Access: https://scholar.colorado.edu/honr_theses/2069; https://scholar.colorado.edu/cgi/viewcontent.cgi?article=3256&context=honr_theses

High snowfall events on Thwaites Glacier (West Antarctica) are a key influencer of its ice mass change. In this study, we diagnose the mechanisms for orographic precipitation on Thwaites Glacier by analyzing the atmospheric conditions that lead to high snowfall events. A high-resolution regional climate model, RACMO2, is used in conjunction with MERRA-2 atmospheric reanalysis to map snowfall and associated atmospheric conditions over Thwaites Glacier and surroundings. We examine these conditions during high snowfall events over Thwaites Glacier to characterize the drivers of the snowfall and their spatial and temporal variability. In addition, we examine correlations of snowfall with the position and strength of the regionally dominant atmospheric pressure system known as the Amundsen Sea Low. Understanding the large-scale atmospheric drivers of snowfall events helps us to recognize how these atmospheric drivers and consequent snowfall climatology may change in the future, which will ultimately improve predictions of accumulation on Thwaites Glacier.