Testing OAFlux Field by Using the Shipborne Heat Flux Measurements

The OAFlux (Objectively Analyzed air-sea Fluxes) database, provided by the Woods Hole Oceanographic Institution, and widely applied in the validation of climate models, is tested by using the TOGA COARE and KAWJEX measurements which are two serial survey databases of NOAA ETL(Environmental Technology Laboratory). The result shows that the latent heat flux of OAFlux is systematically higher than that of ETL, and the difference between them is comparatively large when the heat flux is large itself. Wind velocity plays a dominant role on the change of latent heat when the influence of humidity difference is minimal. In addition, when the sea surface temperature, air temperature, and wind direction do not vary much, the latent difference between OAflux and direct measurements is significant under medium to large wind speed condition and is minimal under the low wind condition. Meanwhile, the sensible heat exchange is very weak and the values are still mainly controlled by wind speed. However, the values of the measured sensible heat flux are very close to the instrument error, leading to difficulty in comparison analysis. The result also shows that the interaction between air and sea mainly depended on the wind velocity when the humidity difference between sea surface and air did not change much during the experimental periods.