Ice-Core Study of the Link between Sea-Salt Aerosol, Sea-Ice Cover and Climate in the Antarctic Peninsula Area.

Abstract Three ice cores and a set of snow pit samples collected on James Ross Island, Antarctic Peninsula, in 1979, 1981 and 1991 have been analyzed for water stable isotope content dD or d18O (isotopic temperature) and major chemical species. A reliable and detailed chronological scale has been established first for the upper 24.5 m of water equivalent (19901943) where various data sets can be compared, then extended down to 59.5 m of water equivalent (1847) with the aid of seasonal variations and the sulphate peak reflecting the 1883 Krakatoa volcanic eruption. At James Ross Island, sea-salt aerosol is generally produced by ice-free marine surfaces during the summer months, although some winter sea-salt events have been observed. For the upper part of the core (19901943), correlations (positive or negative) were calculated between isotopic temperature, chloride content (a sea-salt indicator), sea-ice extent, regional atmospheric temperature changes and atmospheric circulation. The dD and chloride content correlation was then extended back to 1847, making it possible to estimate decadal sea-ice cover fluctuations over the study period. Our findings suggest that ice-core records from James Ross Island reflect the recent warming and sea-ice decrease trends observed in the Antarctic Peninsula area from the mid-1940s. [ABSTRACT FROM AUTHOR]