By correcting Geosat altimetric data for a set of line frequencies, and then doing a heavy average in space and time, a set of global maps of sea surface variability is produced over time intervals ranging from three months to two years. These maps are demonstrated to be consistent with the global network of tide gauges and sets of maps incorporating those data into the altimetric estimates are also produced. Tide gauge records too fragmentary for computation of a two-year mean are employed by time differencing them. An estimate of the global difference of sea level change over one year, on very large space scales, shows the effects of the 1987 El Ni¿o. The spherical harmonic coefficients employed in the computations are then used to estimate the full three-dimensional frequency/wavenumber spectrum of surface circulation variability. ¿ American Geophysical Union 1991