Modeled surface dynamic height in 1964-1984 : an effort to assess how well the low frequencies in the Equatorial Atlantic were sampled in 1982-1984

A wind-forced linear model has been used to produce 21 years (1964--1984) of monthly time series of surface dynamic height in the Equatorial Atlantic. Theclimatological seasonal cycle is substracted, and the statistical characteristics of the residuals are analyzed. An empirical orthogonal function analysis reveals that the most significant pattern has deviations of one sign in the Western Equatorial Atlantic. The anomalies in the last 2 years, 1983 and 1984, are particularly large. The time component of the first empirical orthogonal function peaks in july 1983, changes sign at the end of 1983, and has an extremun of the opposite sign in April 1984. At that time, the zonal slope of dynamic height had reversed with respect to normal along the equator. (D'aprèsrésumé d'auteur