Observed deviations of monthly mean sea level at seven island stations along the equator in the Pacific have been superimposed on the mean dynamic topography to determine the variations of the east-west slope of sea surface topography during the 1982/1983 El Ni¿o. The normal east-west slope is eliminated in January 1983 when the bulk of warm water flowing eastward has reached the coast of South Africa. The sea surface remains essentially flat from January to June 1983, although zonal winds are very weak until April only. The slope requires several months to be reestablished, and in October and November, sea level along the entire equator is 10 cm or more below normal, indicating a net loss of warm water from the equatorial Pacific.