A study of Legeckis eddies in the equatorial Pacific during seasonal periods of high zonal shear between the Southern Equatorial Current and the Northern Equatorial Counter Current is undertaken. We use both Geosat and TOPEX altimetry data, in combination with advanced very high resolution radiometer (AVHRR) temperature fields and numerical results generated by the Parallel Ocean Climate Model (POCM). Geosat data analyzed using the Marquardt-Levenberg Fourier series algorithm <Dayyani et al., 1996>, exhibit eddy features in good qualitative agreement with both linear stability theory of the zonal barotropic flow and with other independent field and satellite observations. A comparison of sea surface height (SSH) and sea surface temperature (SST) anomaly fields suggests that the phase relation between them may be explained in a first approximation by simple cat's-eye kinematics <Musman, 1989>. This is explored further using the POCM, TOPEX, and AVHRR data. The POCM time series of SST and SSH anomalies obtained during a time of quasi-steady eddy propagation clearly show that the phase ϕ between their respective minima varies continuously with latitude, ranging from near zero at latitudes well below the separatrix of the cat's eye to values approaching &pgr; radians at latitudes near the critical layer of the cat's eye. The unsteady wave systems observed in both the Geosat and TOPEX SSH anomaly data show the birth and death of individual eddies, with a fairly clear trend that births occur 1 ¿N of the zonal wave train while deaths occur only in the latitude of the mature wave train. ¿ 1999 American Geophysical Union