The Relationship Between Air-sea Heat Flux And East Asia Summer Monsoon

A monsoon index based on zonal wind shear was used to define the East Asia summer monsoon onset dates. Based on the datasets from the South China Sea air-sea flux measurement, air-sea heat fluxes were calculated with bulk flux algorithms (COARE3.0) and eddy covariance method. The Characteristic of SCS Monsoon and how the air-sea fluxes varied with the variations of atmosphere and ocean were discussed. Large scale of heat fluxes from COARE3.0 method and NCEP2 reanalysis data product were compared with original heat flux from NCEP2. The method of Empirical Orthogonal Functions (EOF) and Singular Value Decomposition (SVD) were used to analyze the character of field flux distribution of different years and the relationship between flux and sea surface temperature respectively. The results indicated that:1,In 2008, A tropical cyclone during the onset of the SCS monsoon brought remarkable changes to the air-sea variations and fluxes. Heat coefficient and momentum coefficient are functions of wind speed, and the graphs have a transition point at the wind speed 4 meters per second.2,The SST change is ahead of the anomaly of time and intensity of monsoon onset, while the variations of heat flux leads SST change. Heat flux influences the monsoon by SST.3,Heat flux over Kuroshio Current ahead of two to three months influence the East Asia monsoon onset. If it increases, the monsoon onset will be earlier and stronger; conversely, the onset will be later and weaker.