Contrasting Tropical Climate Response Pattern to Localized Thermal Forcing Over Different Ocean Basins

Abstract

We contrast the spatial patterns of tropical climate response to localized thermal forcing over different ocean basins in an atmospheric model coupled to a slab ocean. A localized forcing poleward of the climatological storm tracks produces a tropical climate response pattern that is nearly independent of the forcing location. Regardless of the location of extratropical forcing, a common zonally asymmetric La Niña‐like pattern of sea surface temperature response accompanies a northward shift of the Intertropical Convergence Zone. In contrast, a localized tropical forcing produces essentially opposite tropical climate response patterns depending on the forced ocean basin. The northern tropical Pacific (Atlantic) heating induces a warming (cooling) throughout the tropical Pacific, a weakening (strengthening) of the equatorial Pacific trade winds, and a northward (southward) shift of the Southern Pacific Convergence Zone. Our study provides a pathway forward for improving future projections of tropical climate under different anthropogenic forcing scenarios.