Strong La Niña Induce an Extreme High-Salinity of Dense Shelf Water in the Ross Sea in 2012

The Antarctic Bottom Water (AABW), formed from the Dense Shelf Water (DSW), plays a crucial role in global ocean circulation and climate. Based on Antarctic profile datasets, this study found that the salinity of the DSW in the Ross Sea was exceptionally high in 2012. Further analysis revealed that this highsalinity event was associated with anomalous regional winds and sea ice transport, influenced by La Niña. The strong La Niña event from November 2010 to February 2011 strengthened the Amundsen Sea Low (ASL) and caused its eastward shift. This shift led to enhanced southeasterly offshore winds over the RossAmundsen Sea Connection region, which reduced sea ice transport into the Ross Sea. The resulting decrease in sea ice input increased local sea ice production from March to October 2012, contributing to the highsalinity event through intensified brine rejection. This study highlights the influence of tropical climate variability on the DSW salinity and its impacts on the AABW under climate change.