Classification of CMIP5 Future Climate Responses by the Tropical Sea Surface Temperature Changes

Climate changes for the end of the 21st century projected by Coupled Model Intercomparison Project phase 5 (CMIP5) models are classified into three clusters by a cluster analysis of annual-mean tropical sea surface temperature (SST) change patterns. The classified SST change patterns are featured by the zonal gradient of the change in the equatorial Pacific and inter-hemispheric contrast of the warming. Precipitation and atmospheric circulation responses are composited for the clusters, and their relationships to the SST changes are examined. Precipitation increase is larger where SST warming is larger than surroundings and vice versa. Common precipitation and atmospheric circulation responses for each cluster are found also over tropical lands and the extratropics as well as in the tropical oceans, suggesting that some remote effects of the tropical SST change patterns could be one reason for less agreement among CMIP5 models in climate changes.