SEASONAL INTERACTIONS BETWEEN THE NORTH PACIFIC OCEAN AND THE ATMOSPHERE DURING THE 1960's

Abstract An attempt is made to explain the large-scale seasonal ocean-atmosphere interactions that occurred from 1961 through the winter of 1967–68 and that led to a special “climatic regime” over the North Pacific and North America. This regime was characterized by anomalously warm water over the central ocean, which helped generate atmospheric circulations of a kind favoring the persistence of the warm water, especially in the nonsummer seasons. The prevailing atmospheric circulation generated by the warm water during winter consisted of strong and southward-displaced cyclogenesis that produced a standing (Rossby) long wave downstream, resulting in climatic cooling over the eastern two-thirds of the United States. A theory is advanced for the evolution of atmospheric pressure and sea-surface temperature patterns in other seasons based on theoretical and empirical considerations. The inception of the regime came abruptly in the late summer and fall of 1961, following several years when the eastern North ...