Measurements of sensible and latent heat flux in the western equatorial Pacific Ocean

Abstract

Micrometeorological measurements, including direct eddy‐correlation measurements of heat and moisture fluxes, have been made from shipboard under light‐wind conditions in the western equatorial Pacific warm pool. Air‐sea temperature differences were typically 1.5°–2°C, that is, 1°–1.5°C larger than long‐term averages from merchant ship data. A sea surface “cool skin” of about 0.3°C was observed. Bulk transfer coefficients for both fluxes agree well with the predictions of Liu et al. (1979) in the convective wind speed regime below 4 m s−1. Between 4 and 6 m s−1 values of the neutral exchange coefficients were CEN ‐ 0.89 × 10−3; CHN = 1.03 × 10−3; CDN = 1.16 × 10−3. At zero mean wind speed, latent heat flux is maintained at about 25 W m−2 by convective exchange. Inertial dissipation estimates of the latent heat flux are about 20% lower than the directly measured eddy‐correlation values below 4 m s−1.