A 200-Year Sulfate Record from 16 Antarctic Ice Cores and Associations with Southern Ocean Sea Ice Extent

Daniel Dixon
Climate Change Institute, 5790 Bryand Global Sciences Center
University of Maine, Orono, ME, 04469-5790
TEL: 207-581-2112, FAX: 207-581-1203

Data from sixteen, 50m- to 115m-deep, sub-annually dated ice cores are used to examine the recent spatial and temporal concentration variability of sea salt (ss)SO42- and excess (xs)SO42- over West Antarctica for the last 200 years. The preservation of seasonal layers throughout the length of each record results in a dating accuracy of better than one year based on known global scale volcanic events. Our xsSO42- records with volcanic peaks removed do not display any evidence of an anthropogenic impact on West Antarctic SO42- concentrations but do reveal that a major climate transition takes place over West Antarctica at ~1940.

Based on linear correlation analysis ssSO42- concentrations are higher when sea ice extent (SIE) is greater and xsSO42- concentrations are higher when SIE is lesser. The South Pole receives the majority of its xsSO42- from different sources than the rest of West Antarctica and the Weddell region may be a significant source of aerosol chemistry for eastern West Antarctic sites.