The high MSA (methanesulphonic acid) concentration reflects the proximity of the Weddell Sea, believed to be a region of high marine phytoplankton production. The overall mean nss-SO2-4 (non sea salt sulphate) concentration is about 66% of the total sulphate deposited in snowfall. Low-frequency variations of MSA and ozygen-isotope signals correlate closely, indicating that they may be modulated by similar atmospheric processes. Positive correlations are observed between the oxygen-isotope signature and both MSA and nss SO2-4. A small negative correlation can be seen between both species and the annual duration of sea ice at Scotia Bay, Laurie Island in the South Orkneys, since 1902. -from Author
