Study On Air-sea Heat Fluxes In The Offshore Sea Of China

Based on the NCEP/NCAR monthly-mean datasets, the temporal and spatial variations of air-sea heat fluxes as well as the seasonal,annual and decadal variations over the coastal China Sea are analyzed. The result shows that in the Yellow and East China Sea, both the latent and sensible heat fluxes have maxima in winter time, minima in summer time. In the South China Sea, the latent heat flux has the largest values in both the winter time and summer time,while the sensible heat flux shows different features between northern and southern parts. In northern South China Sea, the sensible heat flux presents the same changes in comparison with those in the East China Sea,but the variations of the sensible heat fluxes in the south part are shown to be small in the whole year. As for the Bohai Sea, both the latent and sensible heat flux are found to be small change. In addition,except for the East China sea,the latent heat flux generally indicates a decreased distribution from north to south, while the annual averaged sensible heat flux shows an increased distribution. The major anomaly areas are the Kuroshio extension of the East China Sea and the center of the South China Sea. The annual variations of the heat flux show a increasing trend in the East China Sea , and a decreasing trend in the South China Sea. Changes of the net heat flux are shown to be almost the same as that of the latent and sensible in the north area,while in the southern South China Sea, the net heat flux is the same as the latent heat flux change.Moreover,correlation analyses of the fluxes are also made with the SST,wind speed,difference in air-sea temperature and precipitation in the present study,respectively. The results show that the wind speed and difference in air-sea temperature is not only to the closely relate with the latent heat flux,but has substantial impact on the latent heat flux as well. The precipitation also has significant influences on the latent heat flux,which is larger in the South China sea than that in the East China Sea. The latent heat changes are found to be comparatively consistent with the SST in the East China Sea,However, compared with the SST in the South China Sea,which presents 2 months time-lag. As for East China Sea, wind speed, precipitation, difference in air-sea temperature and SST change depicts fairly good agreement with the sensible heat flux. To future analyze the latent and sensible change, influences of El Nino(La Nina) are also taken into account.