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. Plain Language Summary Following many years of increase, Antarctic sea ice showed a strong decrease in spring 2016. Studies have suggested that remote influences from the tropical Indian and Pacific Oceans may have contributed to this change in sea ice behavior. We use a coupled climate model to investigate the influence of the Indian and Pacific Oceans on Antarctic sea ice during spring 2016. Our model suggests that a remote influence from the tropical Indian Ocean contributed to the sea ice decline during spring 2016, with less influence from the Pacific Ocean. Our model further suggests that intrinsic variability and ocean conditions also contributed to the unexpected Antarctic sea ice behavior in 2016. Key Points Coupled climate model experiments are conducted to investigate the decline of Antarctic sea ice during spring 2016 Our experiments suggest that a tropical Indian Ocean teleconnection contributed to the sea ice decline Less influence from the tropical Pacific Ocean is found in our experiments