宁夏夏季降水变化及对前期高度场异常的响应初探

Primary Exploration on Variation of Precipitation in Summer in Ningxia and Its Response to Prior Sublime Geopotential Height

采用NCEP/NCAR提供的1961～2008年全球100 hPa和500 hPa高度场资料,以及宁夏气象信息中心提供的宁夏全境19个观测站夏季降水资料,利用EOF分解、相关普查和距平合成方法,分析前期1～5月全球100 hPa和500 hPa高度场与宁夏夏季降水量的相关关系,寻找显著相关区。结果表明:前期100 hPa和500 hPa高度场和宁夏夏季降水量之间存在显著相关关系,降水偏多年和偏少年对应的高度场距平合成分布具有相反的特点,偏多年的正距平中心对应偏少年的负距平中心,正、负距平的中心位置基本一致,与对应各月的显著相关区具有一定的一致性。

Based on the global 100 hPa and 500 hPa mean geopotential height data during 1961~2008 provided by NCEP/NCAR,and the summer precipitation data of 19 observation stations in Ningxia,the correlation between the global 100 hPa or 500 hPa geopotential height from January to May and the summer precipitation in Ningxia was studied by using Empirical Orthogonal Function（EOF） analysis,correlation general survey and departure synthesis method.The results indicated that there was significant correlation between 100 hPa and 500 hPa prior mean geopotential height and the precipitation in summer.The departure synthetic distribution of geopotential height in more precipitation year was opposite to that in less precipitation year,the centre of pleion in more precipitation year was corresponding with the meions in less precipitation year,and the central position of pleion and negative departure zone was almost the same,which had a certain consistency with the significantly correlated region of every month.