Spatiotemporal evolution of sea ice and its teleconnections with large-scale climate indices over Antarctica.

ABSTRACT

Sea ice variability patterns are highly influenced by several large-scale ocean-atmospheric oscillations. We analysed both statistical and wavelet coherence methods to examine sea ice's interannual and interdecadal variability. During the past 42-year, the total Southern Ocean sea ice extent (SIE) has expanded, while the Amundsen-Bellingshausen Sea SIE has decreased. A wavelet coherence analysis (WCA) of El Niño Southern Oscillation (ENSO) and the SIE in various sectors revealed an out-of-phase correlation between the Indian Ocean and the Ross Sea. There are significant out-of-phase correlations between sea ice variability and Indian Ocean Dipole (IOD) on an interannual scale. A consistent phase relationship was seen between SIE and Southern Annular Mode (SAM) over the past decade, with in-phase relationships advancing to out-of-phase relationships. The Interdecadal Pacific Oscillation (IPO) shifted from positive to negative after the 1990s. In recent years, SAM has had a stronger impact on sea ice variability than ENSO.