Teleconnections between Tropical Pacific Precipitation and Extratropical Northern Hemisphere Climate in a Warmer Climate

Abstract:

Global temperature is expected to increase further during the 21^st century. Thus, it is great of importance to understand how future climate would be changed in a warmer climate. In this study, we examine the relationship between changes in tropical Pacific precipitation and extratropical Northern Hemisphere climate in response to greenhouse warming. By analyzing the CMIP5 climate models, it is found that the change in latitudinal position of Inter-tropical Convergence Zone (ITCZ) is closely related to the strength of the Northern Hemisphere surface warming in a warmer climate. That is, the global warming due to the increase of greenhouse concentration causes the change in the ITCZ, in turn, the meridional shift of ITCZ can contribute to accelerate or attenuate the surface warming further by changing large-scale atmospheric circulation over the Northern Hemisphere. Specifically, the extratropical Northern Hemisphere surface warming tends to be stronger (weaker) in the models where the ITCZ shifts relatively more northward (southward).