Tropical Teleconnections to Antarctic Sea Ice During Austral Spring 2016 in Coupled Pacemaker Experiments

Following a multidecade increase, Antarctic sea ice declined drastically during austral spring 2016. Suggested causes of the sea ice decline include lingering effects of the 2015/2016 extreme El Niño and a tropical Indian Ocean teleconnection to high-latitude atmospheric circulation. Here, we conduct pacemaker experiments using a full coupled climate model forced with observed tropical sea surface temperature to examine the impact of the Indian and Pacific Oceans on southern high latitudes during spring 2016. Our experiments suggest that a Rossby wave teleconnection from the tropical Indian Ocean contributed to the sea ice decline during spring 2016, with less influence from the Pacific Ocean. However, we find considerable spread in the magnitude of sea ice anomalies across ensemble members, suggesting that while an Indian Ocean teleconnection likely played a role, intrinsic atmospheric variability and high-latitude ocean conditions may also have been important in driving the observed 2016 spring sea ice decline.