An updated Antarctic melt record through 2009 and its linkages to high-latitude and tropical climate variability

A 30-year minimum Antarctic snowmelt record occurred during austral summer 2008-2009 according to spaceborne microwave observations for 1980-2009. Strong positive phases of both the El-NiĂąo Southern Oscillation (ENSO) and the Southern Hemisphere Annular Mode (SAM) were recorded during the months leading up to and including the 2008-2009 melt season. The 30-year record confirms that significant negative correlations exist at regional and continental scales between austral summer melting and both the ENSO and SAM indices for October-January. In particular, the strongest negative melting anomalies (such as those in 2008 and 2009) are related to amplified large-scale atmospheric forcing when both the SAM and ENSO are in positive phases. Our results suggest that enhanced snowmelt is likely to occur if recent positive summer SAM trends subside in conjunction with the projected recovery of stratospheric ozone levels, with subsequent impacts on ice sheet mass balance and sea level trends.