Quasi-Decadal Circumpolar Variability of Antarctic Sea Ice

Abstract

Decadal variability of Antarctic sea ice and a role of ocean dynamics are examined with sea ice concentration (SIC) and sea surface temperature (SST) derived from satellite micro-wave observation and obtained by a high resolution coupled ocean-atmosphere-ice general circulation model (CGCM) . Sea ice observations revealed a circumpolar variability of sea ice edge (SIE) on quasi-decadal time scale. SST also showed variation on similar time scale with warm (cool) anomaly roughly corresponding to retreat (extension) of SIE at negative (positive) southern annular mode (SAM). CGCM run without anthropogenic forcing and volcanic eruptions revealed that the leading mode of SIC is quasi-circumpolar pattern with a dominant time scale of 12-17 years. ocean-atmosphere-ice general circulation model (CGCM) . Sea ice observations revealed a circumpolar variability of sea ice edge (SIE) on quasi-decadal time scale. SST also showed variation on similar time scale with warm (cool) anomaly roughly corresponding to retreat (extension) of SIE at negative (positive) southern annular mode (SAM). CGCM run without anthropogenic forcing and volcanic eruptions revealed that the leading mode of SIC is quasi-circumpolar pattern with a dominant time scale of 12-17 years.