Influence of precipitating convection on the surface energy budget observed during a tropical ocean global atmosphere pilot cruise in the tropical western Pacific Ocean

Abstract

A short‐term observational study of the surface energy budget of the equatorial western Pacific Ocean was conducted in preparation for the Tropical Ocean and Global Atmosphere program Coupled Ocean‐Atmosphere Response Experiment (TOGA COARE). Data were obtained between February 17 and March 10, 1990, during the TOGA pilot cruise of the R/V Wecoma near the equator and 147°E longitude. Analysis of the 443 hours of turbulent and radiative fluxes collected was focused on the influence of deep precipitating convection on the day‐to‐day variability of the surface energy budget. Partitioning the data series according to the degree of local convective activity allowed comparison of the surface energy budgets for various convective regimes. As was observed in the tropical Atlantic during the GARP Atlantic Tropical Experiment (GATE), the surface fluxes of sensible and latent heat were larger during periods influenced by deep precipitating convection. Moreover, the mechanisms by which convection affected these fluxes were similar to those described in the tropical Atlantic. Variations in the shortwave radiation caused by convective clouds and their by‐products were found to contribute even more than the surface fluxes to the day‐to‐day variability of the surface energy budget. It is concluded that the existence of convectively disturbed days had a significant impact on the surface energy budget for the entire cruise period as well as on the day‐to‐day variability within that period.