Amundsen Sea Sea-Ice Variability, Atmospheric Circulation, and Spatial Variations in Snow Isotopic Composition from New West Antarctic Firn Cores

Alison Criscitiello, Ph.D., 2014
Sarah Das, Advisor

Recent work has documented dramatic changes in the West Antarctic Ice Sheet (WAIS) over the past 30 years due largely to the influence of the marine environment.  WAIS is particularly vulnerable to large-scale atmospheric dynamics that remotely influence the transport of marine aerosols to the ice sheet.  Understanding seasonal- to decadal-scale changes in the marine influence on WAIS is vital to our ability to predict future change.  In this thesis, I develop tools that enable us to reconstruct the source and transport variability of marine aerosols to West Antarctica in the past.  Results indicate that firn-core glaciochemical records from this dynamic region may provide a proxy for reconstructing Amundsen Sea and Pine Island Bay polynya variability prior to the satellite era.  I show that source and transport of marine aerosols and the isotopic signal to WAIS are controlled by remote atmospheric forcing, linking local dynamics with large-scale teleconnections to the tropics.  Finally, I investigate longer-term (~200 year) ocean and ice-sheet changes using the methods and results gleaned from the previous work.  I utilize sea-ice proxies to reconstruct long-term changes in sea-ice and polynya variability in the Amundsen Sea, and show that the tropics remotely influence West Antarctica over decadal timescales.