The cooling of the Southern Ocean, despite global warming trends, has been proven through a combination of satellite data, ocean temperature records, and climate models. One of the key pieces of evidence comes from satellite observations that have tracked the movement of ice melt from Antarctica’s ice shelves. The Antarctic Peninsula and West Antarctica have seen substantial ice loss, contributing vast amounts of meltwater into the Southern Ocean, particularly in regions like the Amundsen and Bellingshausen seas. These areas, where ice loss has accelerated in recent decades, show a marked increase in freshwater influx, which has been observed to reduce surface salinity and hinder ocean mixing.
Geographically, the Southern Ocean surrounding Antarctica is an important site for heat exchange, as it typically absorbs about 40% of the heat trapped by greenhouse gases. However, scientific measurements have shown a significant reduction in this heat absorption since the early 2000s. Research teams from institutions like the University of Tasmania and the British Antarctic Survey have documented these changes through ocean buoy data and temperature profiles, which reveal a cooling effect in the upper ocean layers, particularly near the Antarctic Circumpolar Current. These findings confirm that the added freshwater from melting ice has created a layer of cold, less-dense water that has been preventing the usual vertical mixing that would typically bring heat from the deep ocean to the surface. Additionally, climate models now account for these changes in ocean stratification, which were previously underestimated in traditional models. This new understanding has major implications for predicting future climate dynamics and the role of the Southern Ocean in regulating global temperatures. More