Breakup of land-fast sea ice in Lützow-Holm Bay, East Antarctica, and its teleconnection to tropical Pacific sea surface temperatures

Abstract

A large land-fast sea ice breakup occurred in 2016 in Lützow-Holm Bay, East Antarctica. The breakup caused calving from the Shirase Glacier Tongue. Although similar breakups and calving have been observed in the past, the timing and magnitudes are not well-constrained. The ice's breakup latitude during 1997–2016 was analyzed to investigate the variables controlling breakup and examine correlation with local calving for a longer period. The breakup latitude in April had a persistently high correlation with sea surface temperature (SST) in the tropical Pacific, which exceeds correlations with local atmospheric variables. The years of five out of six observed calving events from the mid-20th century can correspond to those of warm SST episodes and calving-front retreat in the 1980s to warmer SST shift. Our proposed teleconnection between tropical SST and Antarctic sea ice could lead to better predictions of breakup and might impact the glacier flux for a wider region.