New method reconstructs global ocean heat distribution

A European research team has developed a new method to reconstruct the monthly distribution of ocean heat content between 2005 and 2024. The approach combines three distinct types of observations: gravity changes detected by the GRACE and GRACE-FO satellite missions, sea surface height measured by satellite altimeters, and temperature and salinity profiles from autonomous Argo buoys.

By integrating these data sets, researchers can distinguish between sea-level rise caused by added water mass and that caused by the thermal expansion of warming water. While global averages from this method align with existing climate models, the study revealed significant discrepancies in specific ocean basins, with differences reaching double digits in some cases.

The findings indicate that the Pacific, Atlantic, and Indian Oceans have each absorbed approximately one-third of the Earth's excess heat over the last 20 years. Notably, the Indian Ocean absorbed an unusually high amount of heat between 2005 and 2015, suggesting a complex transfer of heat between different oceanic basins.