Air-Sea Flux Exchange over the Xisha Sea Area Before and After the Onset of Southwest Monsoon in 2002

Abstract

The third South China Sea (SCS) air-sea flux experiment was conducted in Xisha sea area from April 24 to June 22, 2002. The heat flux (latent and sensible heat) exchange and momentum exchange were computed using eddy-correlation method and TOGA COARE2.5b algorithms. Variation of radiation components, heat and moisture flux exchange and their relations with synoptic condition were discussed. The results indicate that heat and moisture fluxes, especially short-wave radiation, net radiation budget of ocean surface, latent heat flux and net oceanic heat flux, changed significantly before and after the onset of SCS monsoon in that year. Relationships of sensible heat flux, latent heat flux and momentum fluxes with different environment elements are different. Sensible heat flux has positive correlation with air-sea temperature difference Tw – Ta. Latent heat flux has positive correlation with wind speed V,Tw–Ta and SST, especially with wind speed. Momentum fluxes vary with wind speed (V) as a function of = 0.00185V 2 – 0.00559V + 0.01248.