Extended Data Fig. 4: Wider climatic conditions over the Weddell Sea Sector.
From: Antarctic ice-shelf advance driven by anomalous atmospheric and sea-ice circulation
a and b, Monthly changes in the Interdecadal Pacific Oscillation (IPO) and Southern Annular Mode (SAM), respectively (Methods). Data have been smoothed using a 20-year running mean to emphasise multi-decadal variability. Following Fig. 2, blue (pink) shading denotes the approximate timing of relatively cool (warm) climatic conditions over the Antarctic Peninsula as deduced from (a). c and d, annual-averaged 10 m wind anomalies over the Antarctic Peninsula Ice Sheet for the periods (c) January 1982 to December 2002 and (d) January 2003 to December 2019, respectively, relative to all months on record (1979–2019). Note the abrupt reversal in wind direction over most EAP ice shelves (except Ronne) between the two periods, indicative of reduced foehn wind-driven ice-shelf surface melting, calving and coastal sea-ice evacuation through time (see main text and Supplementary Discussion 3 for further information).
