南半球高纬地区前期环流异常和我国华北地区夏季降水的联系

THE RELATIONSHIP BETWEEN THE NORTH CHINA SUMMER PRECIPITATION AND THE PREVIOUS CIRCULATION ANOMALY AT HIGH LATITUDE IN SOUTH HEMISPHERE

关键词:  华北夏季降水  南半球环流异常  华北地区夏季降水指数(RI)  南半球环流异常指数(IDX)

Key words:  summer precipitation in North China  circulation anomaly in South hemisphere  RI index describing the summer precipitation in North China  IDX index describing the circulation anomaly in South hemisphere

摘要:

利用1951~2000年共50年中国160个站的逐月降水与地面气温资料以及美国NCEP/NCAR全球再分析资料,找出了影响华北地区夏季降水的南半球关键区——50~60°S。研究结果表明,该区前期1月份的环流异常能够影响当年夏季华北地区的降水,反映这种异常的指数IDX高时,华北夏季降水偏少;IDX偏低,华北夏季降水偏多。

Abstract:

Based on the monthly rainfall and surface air temperature data of 160 stations in China and the NCEP/NCAR reanalysis data from 1951 to 2000,a key region in 50~60°S where the January circulation anomaly may influence the summer precipitation in North China is found.An index(IDX) that is used to describe the circulation anomaly and forecast the rainfall anomaly in North China is defined,too.The results show that when IDX is higher,the precipitation in North China will be less and vice versa.