In November--December 1992 we measured microstructure, the hydrographic field, and the velocity field in the western equatorial Pacific near 1¿43'S and 156 ¿E as the first part of the Tropical Ocean - Global Atmosphere - Coupled Ocean Atmosphere Response Experiment. During our stay, we observed two westerly wind bursts with maximum speeds of about 10 m s-1, rainfalls of about 20 mm h-1, and nearly 2 weeks of calm and dry weather. During wind bursts, mixing in the upper 1 MPa was dramatic and rapid, and the major turbulence in the thermocline was produced by near-inertial shears following the wind bursts, during which dissipation rates and Richardson numbers were comparable to those in the central Pacific. By the end of the October--November westerly burst, the averaged eddy diffusivity of momentum in the mixed layer was about 10-2 m2 s-1. Below the mixed layer, a layer about 0.50--0.75 MPa thick with high shear and strain along with a high dissipation rate persisted even after the wind burst. During calm days, mixing was primarily driven by nighttime convection and was confined to the upper 0.1 or 0.2 MPa. In general, no diurnal deep cycle in dissipation rate was found below the mixed layer, unlike in the central equatorial Pacific. Entrainment below the mixed layer occurred when both wind work and convection were large. On average, the entrainment heat flux at the base of the mixed layer was about 6 (¿2) W m-2. Salinity gradients were important to density between 0.3 and 0.6 MPa. However, the salinity stratification did not control entrainment mixing. During calm and dry weather, the mixed layer heat content was governed by the vertical divergence of the radiative flux, that is, the net surface heat flux minus the radiative flux out the bottom of the layer. Both the entrainment flux and the advective flux (which was estimated as the residual term) were smaller than uncertainties in the surface heat flux. During the October--November wind burst, however, the advective term was one of the most dominant terms in the heat budget. Although the entrainment heat flux was small over short timescales, it may be important in long-term budgets because the long-term net surface heating could also be small. ¿ American Geophysical Union 1996