Axel Timmermann, Jung-Eun Chu, Sun-Seon Lee, Christian Wengel, Malte F. Stuecker, Ryohei Yamaguchi

Tropical cyclones (TCs) are extreme storm systems that form over warm tropical oceans. Along their track TCs can mix up cold water which can further impact their development. Due to the adoption of lower ocean model resolutions, previous modeling studies on the TC response to greenhouse warming underestimate such oceanic feedbacks. To address the robustness of TC projections in the presence of mesoscale air-sea interactions, we conduct century-long present-day, CO2 doubling and quadrupling experiments using the Community-Earth-System-Model 1.2.2 with ~25 km atmosphere and ~10 km ocean resolution. In these experiments an overall projected weakening of the rising branch of the Hadley Cells suppresses TC formation in the main genesis regions which weakens the TC-generated ocean cooling. Consistent with lower-resolution coupled modeling studies we find a reduction in global TC frequencies, a poleward shift of fast-moving extratropical TCs and an upsurge in precipitation rates and the intensity of landfalling events.