From February 1983 through September 1984, 18 inverted echo sounder deployments yielded time series from 10 locations as part of the Seasonal Response of the Equatorial Atlantic (SEQUAL) program. Using historical and in situ data, the sounders' travel time data are interpreted as dynamic height (0 relative to 500 dbar) and then related to representations of the synoptic wind field. The seasonal variations of the zonal pressure gradient along the equator and the height of the dynamic ridge along 3¿N relative to the equator and 9¿N are described. The pressure gradient between 10¿W and 34¿W has a minimum each April and a maximum each July. Its value ranges between 1.4 (not significantly different from zero) and 8.3 ¿ 10-5 dyn g-1 during the observational period. The zonal pressure gradient is correlated with zonal wind stress from an in situ wind sensor at midfetch, and a 10-day lag time is indicated. The North Equatorial Countercurrent trough attains a maximum in the late boreal summer and fall and a minimum in the spring. It ranges from +39 to -8 dyn cm deep at 38.5¿W and from 18 to - 1 dyn cm at 28 W. A two-layer model calculation, using monthly mean winds derived by Servain et al. (1986) for the appropriate time period, generally reproduces the observed seasonal variation along the two meridians and the large zonal variation between them. Tracking the individual terms, month by month, illustrates the rate of the Sverdrup adjustment to the local wind stress with surface elevation rising as fast as 10 cm per month. ¿American Geophysical Union 1987