Antarctic Meltwater Cools Southern Ocean, Defying Climate Models

Contrary to climate model predictions, the Southern Ocean around Antarctica has cooled over the past 40 years. Stanford University scientists discovered that meltwater from Antarctic ice sheets and increased precipitation are key factors. This freshwater reduces ocean salinity, preventing warmer deep waters from rising, creating a cooling "lid" at the surface. The study, published in Geophysical Research Letters, reveals that up to 60% of the mismatch between observed and simulated surface temperatures can be attributed to missing freshwater inputs in climate models. This localized freshwater input near Antarctica significantly impacts sea ice formation and sea surface temperature. These findings highlight the importance of accurately representing freshwater inputs in climate models for predicting global climate impacts, including sea level rise and El Niño/La Niña patterns.