A multivariate analysis of Antarctic sea ice since 1979

Abstract

Recent satellite observations have shown an increase in the total extent of Antarctic sea ice, during periods when the atmosphere and oceans tend to be warmer surrounding a significant part of the continent. Despite an increase in total sea ice, regional analyses depict negative trends in the Bellingshausen-Amundsen Sea and positive trends in the Ross Sea. Although several climate parameters are believed to drive the formation of Antarctic sea ice and the local atmosphere, a descriptive mechanism that could trigger such differences in trends are still unknown. In this study we employed a multivariate analysis in order to identify the response of the Antarctic sea ice with respect to commonly utilized climate forcings/parameters, as follows: (1) The global air surface temperature, (2) The global sea surface temperature, (3) The atmospheric CO2 concentra- ̃ tion, (4) The South Annular Mode, (5) The Nino 3, (6) The ̃ ̃ Nino 3 ? 4, 7) The Nino 4, (8) The Southern Oscillation Index, (9) The Multivariate ENSO Index, (10) the Total Solar Irradiance, (11) The maximum O3 depletion area, and (12) The minimum O3 concentration over Antarctica. Our results indicate that western Antarctic sea ice is simulta- neously impacted by several parameters; and that the min- imum, mean, and maximum sea ice extent may respond to a separate set of climatic/geochemical parameters.