The role of wind driven ocean circulation changes in climate change in CESM2

Mitigation and adaptation strategies for climate change depend on improving climate models. One source of uncertainty in climate models is the response of the atmospheric circulation. A changing atmospheric circulation can alter the surface wind stress, which will alter the ocean circulation. The changes to the wind driven ocean circulation can then redistribute heat, with impacts to local, regional, and global climate. I will illustrate two examples within a CESM2 model ensemble hierarchy framework. Changes to the wind driven ocean circulation over the historical period amplify externally forced warming by 17%. This is primarily driven by weakened trade winds over the Pacific. Wind driven ocean circulation changes also alter the timing of the projected North Atlantic warming hole.