青藏高原加热场与长江下游秋季降水的关系

Relationship of Surface Heating Field in the Tibetan Plateau and Autumn Precipitation in the Lower Reaches of Yangtze River

利用1960年至2010年青藏高原地面加热场强度距平指数,中国月平均降水资料以及NCEP/NCAR再分析资料,分析了冬季高原地面加热场强度变化趋势,长江下游地区秋季(9,10月)降水量时空变化,着重对冬季高原地面加热场强度与次年长江下游地区秋季降水做相关性分析,配合冬季高原地面加热场强度极值年对应的秋雨时期环流情况,得出以下结论:(1)冬季高原地面加热场强度年际变化显著,自1960年来大幅下降,2000年后小幅回升但仍未达到先前水平。(2)长江下游地区秋季降水主要集中在9月,且降水量呈同多同少分布,年际变化显著,1985年后降水总量偏少。(3)冬季高原地面加热场强度与长江下游地区秋雨降水量存在相关关系。冬季高原地面加热场强时,次年长江下游地区秋季降水量大,其中部分地区相关性非常显著;反之当冬季高原地面加热场强度弱时,次年长江下游地区秋季降水量也较小。

Based on surface heating field anomaly index in the Tibetan Plateau from 1960 to 2010, the mean monthly precipitation data and NCEP/NCAR reanalysis data, variation trend of the surface heat field in plateau of winter, temporal and spatial variation of autumn precipitation in the lower reaches of Yangtze river was analyzed, and the correlation between strength of the surface heat field in plateau of winter and the following autumn rainfall in the lower reaches Yangtze river were analyzed. It shows that （ 1 ） the interannual intensity of the surface heat field in plateau of winter is significant, it has fallen sharply since 1960 and modestly has risen after 2000 but still not reach the previous level; （2） the autumn precipitation in the lower reaches Yangtze river mainly concentrated in September, and rainfall is direct ratio distribution and interannual changes significantly, total precipitation is less after 1985; （3） there is the correlation between strength of the surface heat field in plateau of winter and autumn rainfall relationship in the lower reaches of Yangtze river.