Tropical forcing of West Antarctic ice Sheet surface mass balance variability

• Main Author: Krueger, Dennis J.
• Other Authors: College of Social & Behavioral Science, Geography
• Format: Text
• Language: English
• Published: University of Utah 2019
• Subjects: Antarctic; Amundsen Sea; West Antarctic Ice Sheet; Pacific; Indian; Antarc*; ice core; Ice Sheet
• Online Access: https://collections.lib.utah.edu/ark:/87278/s6pc93hw

thesis The climate mechanisms influencing surface mass balance (SMB) variability on the West Antarctic Ice Sheet (WAIS) are highly varied and complex. Most research has focused on the role of the Pacific Ocean region with regards to WAIS climatology. Known phenomena such as the Amundsen Sea Low, Southern Annular Mode, and the El Niño Southern Oscillation interact and affect WAIS climate to varying degrees. Little attention, however, has been paid to the potential effects of the Indian Ocean on WAIS SMB. In this study, we use reanalysis data to examine both the tropical Pacific and Indian Oceans for sea surface temperature (SST), outgoing longwave radiation, 200 hPa height, and vertically-integrated moisture flux patterns evident in the SMB record of the WAIS, as indicated by 39 ice core records covering a temporal range of 1850-2010. We examine anomalies in these variables and carry out maximum covariance analysis to examine the climate setups associated with WAIS SMB variability. A dipole in central tropical Indian Ocean SSTs suggests greater variability in WAIS SMB. Specifically, a dipole of warm eastern Indian Ocean and cool western Indian Ocean SSTs suggests above average WAIS SMB. A reversed Indian Ocean SST pattern, alongside a La Niña-like pattern in the tropical Pacific Ocean, suggests below average WAIS SMB. Analysis of atmospheric variables also supports this pattern.