PROPAGATION OF LOW FREQUENCY SEA SURFACE TEMPERATURE ANOMALIES IN THE NORTH PACIFIC

V. I. Ponomarev, O. O. Trusenkova, and S. T. Trusenkov

The propagation of sea surface temperature (SST) anomalies in the Pacific Ocean north of 20ºN with the periods of 3—12 years was analyzed. The expansion in the complex empirical orthogonal functions was applied to monthly mean SST anomalies for the period of 1947—1978. Anomaly pattern and movement corresponding to the first complex mode are in agreement with the El Nino signal propagation in the East Pacific. The second complex mode has the highest amplitude in the Kuroshio—Oyashio energy active zone. Winter SST anomalies associated with this mode propagate in the opposite directions from the Northwest Ridge and Hess Rise. Statistically significant unlagged and lagged cross-correlation was found between the temporal mode amplitudes and El Nino index which emphasizes the feedback between midlatitude SST anomalies and the ENSO cycle.