Comparative analysis of tropical convection feature and strong weak cases of south china summer monsoon circulation

Strong and weak summer monsoon years over south china sea were Synthesis analysed by employing NCEP/NCAR data, result indicated that whether in forthcoming of the onset of summer monsoon of January or in prevailing summer monsoon of July, the mean meridional circulation and mean zonal circulation in the strong and weak summer monsoon cases is obvious difference. In strong summer monsoon cases, January Hadley circulation and July walker circulation as well as monsoon meridional circulation are stronger than that of weak monsoon cases. The intensity of Western pacific subtropical high in strong summer monsoon cases is weaker than that of weak summer monsoon years. The OLR data were undertaken to analyse interseasonal variability over equatorial eastern Indian ocean and south china sea in stronger summer monsoon year(1981) and weak summer monsoon year(1983) from April through September, respectively. The outcome showed that in strong summer monsoon cases, the times of interseasonal variability is low and the intensity is quite strong, on the contrary, the times of interseasonal variability is high and the intensity is quite weak in weak summer monsoon cases. Compare with South China Sea, the interseasonal variability of equatorial eastern Indian summer monsoon is more typical than that of SCS in SCS strong summer monsoon years.