东亚经向热力差异与华南夏季风及降水年际变化的关系

利用多年海表温度和中国测站近地面温度及降水资料,分析了夏季东亚地区经向热力差异的年际变化与华南夏季降水及华南夏季风环流变化的关系。结果表明:当黄河中下游及其附近地区地表气温偏高(低),华南偏低(高),则华南降水偏多(少),而江黄流域降水偏少(多)。在东亚地区夏季经向热力差异指数偏强年,南海北部至华南地区的夏季西南季风偏强,华南夏季降水偏多;弱指数年情况相反。

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.