90年代西太平洋副高异常的分析

西太平洋副热带高压的活动是影响我国东部降水的主要因子之一。监测和研究副高的活动对预测我国东部汛期降水有重要意义。但９０年代副高特征量出现连续异常，分析指出，特征量的这种异常并不代表副高活动真正异常，而是与计算特征量所用资料的变更有关。对１９９１年１１月到１９９６年２月使用Ｔ４２模式资料期间的５００ｈＰａ高度，利用ＮＣＥＰ／ＮＣＡＲ重分析资料进行了订正，并重新计算了此期间的副高诸特征量。

Abnormality of the Indices of Western Pacific Subtropical High during the Early 1990s

During early 1990s,the indices of Western Pacific Subtropical High are abnormal,e.g.,the Area Index and Strength Index of High are too high to be reliable. The possible reason is discussed,and the change of 500hPa geopotential height filed for calculating those indices should be in change of the abnormality. The National Climate Center 500hPa geopotential heights of T42 model from November 1991 to February 1996 are corrected through the NCEP/NCAR reanalysis 500hPa heights. And based on the corrected 500hPa heights,the indices for the abnormal period are recalculated.