青藏高原冬春积雪异常与中国东部地区夏季降水关系的进一步分析

FURTHER ANALYSES OF THE LINKAGE BETWEEN WINTER AND SPRING SNOW DEPTH ANOMALY OVER QINGHAI-XIZANG PLATEAU AND SUM-MER RAINFALL OF EASTERN CHINA

中文关键词:  青藏高原  冬春积雪异常  中国东部夏季雨量  季风环流  积雪影响降水的机理

英文关键词:The QXP, Snow anomaly in winter and spring  The SREC  Monsoon circulation  Effect mechanism of snow on precipitation

中文摘要:

      为了进一步分析青藏高原(下称高原)冬春积雪异常与中国东部地区夏季降水的关系,利用1957～1994年高原地区的实测雪深、1951～1994年6～8月中国东部地区226个均匀分布测站的实测月降水量,以及美国国家环境监测中心/国家大气研究中心(NCEP/NCAR)1958～1994年1～12月的再分析格点值资料,对比分析了高原冬、春季多、少雪年后期中国东部地区夏季(6～8月)降水分布和环流的平均特征,也分析了高原积雪影响的机理。分析结果表明:1)平均来说,多雪年夏季长江及江南北部降水可偏多1～2成,华北和华南的降水则偏少1～3成;少雪年夏季江淮流域及湘、黔地区少雨,华北和华南多雨。2)高原冬、春积雪不仅影响了后期高原的热状况,而且影响了后期东亚大气环流的季节变化和南亚与东亚的夏季风环流。

英文摘要:

      To analyze the linkage between the winter and spring accumulated snow depth over the Qinghai-Xizang Plateau (QXP) and the following summer (June-August) rainfall of Eastern China (SREC), firstly, four typical heavy and light snow years over the QXP in winter and spring were chosen, then, the comparison analysis of the SREC distribution and the atmospheric circulation feature between the heavy and light snow years as well as the impact mechanism of the QXP snow anomaly on the SREC have been done, utilizing the QXP accumulated snow depth data of 1957-1994, the rainfall data of 1951-1994 in 226 stations over Eastern China, and the National Environment Prediction Center/National Center for Atmospheric Research, USA (NCEP/NCAR) reanalysed data of 1958-1994. The main conclusions show that: 1) On the average, in the QXP heavy snow years, Changjiang River and its so uthern side have more summer precipitation with the positive anomaly of 10 to 20 percentage,the southern and the northern China less precipitation with the negative anomaly of 10 to 30 percentage. But in the QXP light snow years, Chang jiang and Huaihe Rivers as well as Guizhou and Hunang provinces have less precipitation, and both the south and north sides of it more precipitation. 2) The QXP snow cover in winter and spring influences, firstly on the subsequent QXP thermal condition, then on the season change of the general circulation in Eastern Asia as well as the summer monsoon systems in Southern and Eastern Asia, again then on the SREC. 3) The effect linkage of the QXP winter snow anomaly on the SREC has been outlined.