The Reemergence of SST Anomalies in the North Pacific Ocean

Abstract

Abstract Sea surface temperature (SST) data and two different upper-ocean temperature analyses are used to study the winter-to-winter recurrence of SST anomalies in the North Pacific Ocean. The SSTs recur when temperature anomalies that form in the deep ocean mixed layer in late winter/early spring are isolated from the atmosphere in the summer seasonal thermocline and then reemerge at the surface when the mixed layer deepens during the following fall/winter. This “reemergence mechanism” is evaluated over the basin by correlating the time series of the leading pattern of ocean temperature anomalies in the summer seasonal thermocline (∼60–85 m in August–September) with SST anomalies over the course of the year. The results indicate that the dominant large-scale SST anomaly pattern that forms in the North Pacific during late winter, with anomalies of one sign in the central Pacific and the opposite sign along the coast of North America, is sequestered in the seasonal thermocline in summer and returns to the...