Regional response of annual- mean tropical rainfall to global warming

Regional response of annual-mean tropical rainfall to global warming is investigated based on 18 models from the Coupled Model Intercomparison Project 5. With surface warming, the climatological ascending circulation pumps up increased surface moisture and leads to a rainfall increase over the convergence zone, while the change in ascending flow induces a rainfall increase over the region with sea surface temperature (SST) increase exceeding the tropical mean, with a concomitant modification of background surface moisture and SST. These two effects form a hook-like pattern of rainfall change over the tropical Pacific and an elliptic pattern over the northern Indian Ocean.