INTERANNUAL VARIABILITY OF THE EQUATORIAL PACIFIC-REVISITED.

A linear numerical model forced by monthly shipboard wind estimates used to study the interannual response of the tropical Pacific Ocean for 1961-1970 is extended through December 1978. The additional 8 years include the 1972 and 1976 Los Ninos and the aborted event of 1975. Model pycnocline variations at several locations are compared with observed sea-level fluctuations. El Nino events are depicted as periods when the pycnocline is persistently deep along the eastern boundary. Remotely forced equatorial Kelvin waves are responsible for this response. The character of each simulated El Nino is strongly dependent on the relation between zonal wind stress changes in the western and central equatorial Pacific. Interannual pycnocline displacements in the central equatorial Pacific are determined by the superposition of Kelvin waves excited to the west and first horizontal-mode Rossby waves generated to the east.