East-Asian Meridional Heat Difference and its Relations with the Summer Monsoon and the Interannual Variation of Rainfall in South China

Multiple-year data of sea surface temperature,near surface temperature and the precipitation in China,are used to investigate the East-Asian meridional heat difference(EAMHD) and its relations with the precipitation over South China in summer and the variation of South China summer monsoon circulation.Results show that,positive(negative) surface temperature anomalies over middle and lower reaches of Yellow River,and negative(positive) anomalies in South China,indicates more(less) rainfall in South China and less(more) rainfall in Yangtze and Yellow River Valleys.In the years of strong EAMHD index,there tends to be stronger summer southwest monsoon from northern South China Sea to South China,and more rainfall in summer of South China.While in the years of weak EAMHD index,it is just the opposite.