Tropical origins for recent North Atlantic climate change

Evidence is presented that North Atlantic climate change since 1950 is link ed to a progressive warming of tropical sea surface temperatures, especiall y over the Indian and Pacific Oceans. The ocean changes alter the pattern a nd magnitude of tropical rainfall and atmospheric heating, the atmospheric response to which includes the spatial structure of the North Atlantic Osci llation (NAO), The slow, tropical ocean warming has thus forced a commensur ate trend toward one extreme phase of the NAO during the past half-century.