Horizontal structure of the upper ocean velocity and density fields in thewestern equatorial Pacific warm pool: Depth range from 20 to 250 m

Wavenumber spectra of velocity and density fields in the western equatorial Pacific warm pool on scales 6-120 km are estimated using the shipboard sur vey data collected during the TOGA Coupled Ocean-Atmosphere Response Experi ment (COARE). The spectra are averaged over three depth intervals: 20-60, 6 0-110, and 110-250 m (corresponding to the Yoshida jet, the South Equatoria l Current, and the southern edge of Equatorial Undercurrent). The velocity spectra are corrected for the mean flow shear advection, which is important under conditions of low gradient Richardson number (Ri). After that, both velocity and density spectra are consistent with an internal wave spectral model including a random component (equatorial version of the Garrett and M unk spectrum) and a tidal component (the Feng et al. tidal model). Tidal pe aks, previously found by other COARE investigators as being prominent on th e "moored" spectra (i.e., on the spectra derived from mooring data), appear to be much less significant on the "towed" spectra (i.e., on the spectra d erived from shipboard surveys). The model and observations reveal some dire ctional anisotropy of the towed velocity spectra depending on Ri.