Record warming in the South Pacific and western Antarctica associated with the strong central‐Pacific El Niño in 2009–10

Abstract

Satellite data for the past three decades reveal a record‐high sea surface temperature (SST) anomaly within a large mid‐latitude region of the south‐central Pacific (SCP) during the mature phase of the 2009–10 El Niño, with a peak magnitude that is 5 times the standard deviation of local SST anomaly and is warmer than the concurrent tropical‐Pacific SST anomaly. The SCP oceanic warming was confined to the upper 50 meters and is associated with an extreme and persistent anticyclone. Wind changes associated with the anticyclone caused the oceanic warming with surface heat flux and ocean processes playing equally important roles. The anticyclone diverted circumpolar westerlies and warm air towards Antarctica. Austral‐summer SST in the Bellingshausen Sea also reached a three‐decade high. The extreme atmospheric and oceanic anomalies in the South Pacific may have been fueled by the 2009–10 El Niño because of its record‐high SST anomaly in the central‐equatorial Pacific.