闭合气压系统环流指数的定义及计算  

Definition and Calculation of Three Circulation Indices for Closed Pressure Systems

作　　者：王盘兴[1] 卢楚翰[1] 管兆勇[1] 李尚锋[2] 姚菊香[1] 严厉[1] 

机构地区：[1]南京信息工程大学大气科学学院,江苏南京210044 [2]吉林省气象局,吉林长春130062

出　　处：《南京气象学院学报》2007年第6期730-735,共6页Journal of Nanjing Institute of Meteorology

基　　金：江苏省气象灾害重点实验室资助项目(KLME060211);国家自然科学基金委重点资助项目(40633018)

摘　　要：定义了球面上单个气压系统的面积S、强度P、中心位置(λc,φc)3种环流指数;结合NCEP/NCAR月平均气压(位势高度)场资料,给出了它们的计算方法。实际计算了历年逐月500hPa北半球极涡的上述环流指数,求得它们的逐月多年平均(气候)值。初步分析表明,它们能简洁定量地描述北半球极涡的季节变化和年际异常特征。S、P、(λc,φc)的定义和算法,也适用于极涡以外的其他闭合气压系统或球面上其他要素场中的闭合系统。Three circulation indices are defined for closed pressure systems, which are area index S, strength index P, center longitude/latitude position index （λc,φc）. Their calculation methods are also put forward by using NCEP/NCAR monthly mean pressure （geopotential height） fields. The above circulation indices of 500 hPa north polar vortex are calculated and their climatological time series are constructed respectively. Results indicate that these three indices can simply and quantitatively describe northern polar vortex＇s seasonal and interannual variability, and also suitable for describing other closed systems of pressure or the other meteorological element fields on the spherical surface.

关 键 词：闭合气压系统 环流指数 定义 500 hPa北半球极涡 

分 类 号：P434[天文地球—大气科学及气象学]