Aircraft observations of the surface energy balance in TOGA-COARE

The TOGA-COARE (Tropical OceadGlobal Atmosphere Coupled Ocean-Atmosphere Response Experiment) was an international observational campaign designed to study the processes that occur in the Pacific warm pool region. Data from the Meteorological Research Flight C130 aircraft are presented to illustrate some of the characteristics of the surface energy balance in this region. The dominant terms in the balance are the turbulent latent-heat flux and the solar flux. The C130 moisture flux data are compared with a parametrization based on data from the RVMoana Wave, one of the ships that took part in the COARE. It is found that there is no evidence for a systematic difference between the aircraft and ship flux estimates. In addition to the comparison with the COARE parametrization the effect of gustiness due to convective clouds on the surface latent-heat flux is estimated for three flights, and the thermal balance of the mixed layer in undisturbed conditions described. The data suggest that direct solar absorption is an important part of the thermal balance, and the implications for diurnal variations in the mixed-layer temperature are considered. The variation in the downwelling solar flux with cloud cover is compared with simple parametrizations, which are found to agree reasonably well with the present data. The correlation between the long-wave and short-wave cloud forcings at the surface are described, to illustrate the different effects of different cloud types on the surface radiative balance.