The Southern Ocean, a vital global carbon sink, is defying climate model predictions by maintaining its capacity to absorb CO2, a phenomenon now potentially explained by a study from the Alfred Wegener Institute (AWI). Researchers have discovered that an increase in cold, low-salinity surface water has been effectively trapping CO2-rich deep ocean water, temporarily offsetting the anticipated weakening of this critical carbon sink due to climate change. “The Southern Ocean’s surface water salinity has reduced… This ‘freshening’ reinforces the density stratification between the two water masses,” explains Dr. Olivier.