Seasonal precipitation variabilities in North America (between 15-55N) and their possible links to global mean sea surface temperature(GMSST) change are studied for the period of 1955-1998. This study is to analyze the impacts of the global change on North America regional climate on the interannual, decadal-to-interdecadal timescales and beyond. Wavelet analysis is used to identify the dominant timescales in GMSST and the SST-precipitation coupled patterns. Preliminary results show that the floods and droughts in North America may be linked to multiple timescales in GMSST variations. On the interannual timescale, a positive GMSST anomaly is associated with summer droughts in the southeastern states and the floods in the states to the south and the east of the Great Lakes. On the decadal-to-interdecadal timescale, a positive GMSST anomaly may result in severe drought in Mexico while flood to its north, i.e., in the middle of the U.S. Due to the global SST warming trend, both Mexico and the coastal states in the southeastern U.S. become drier while most of the North America, especially in the east coast of Canada and the Great Lakes area become wetter.
During winter, a positive GMSST anomaly on the interannual timescale may lead to wetter climate in California, Mexico, the eastern coast of North America and southwest coast of Canada, while most of the rest areas become drier. On the decadal-to-interdecadal timescale, a positive GMSST anomaly may cause Texas wetter while northeast and northwest states of the U.S. drier. The global SST warming trend is associated with a wetter southern U.S. and northern Mexico, and drier northwest coastal states. The impacts of the 1997-98 El Nino event on the anomalous seasonal precipitation distribution in North America are assessed in the aforementioned multi-scale framework.