500hPa距平场的EOF显著性及遥相关分析  

The Estimates of Spatial Degrees of Freedom and EOF Significant Analysis of 500hPa Potential Height Anomaly Field

作　　者：田晨[1] 刘瑾 陈超[1] 

机构地区：[1]南京信息工程大学,江苏南京210044 [2]河北省邢台市气象局,河北邢台054500

出　　处：《安徽农业科学》2011年第4期2028-2032,2074,共6页Journal of Anhui Agricultural Sciences

摘　　要：利用空间自由度估计和自然正交展开（EOF）显著性检验方法对1948~2005年北半球冬季1月份和夏季7月份的500 hPa位势高度场进行分析,并用前10个特征值与相对应的EOF进行显著性检验。结果表明,1月份,前8个EOF比较显著,而7月份则是前9个EOF比较显著。对冬夏季前4个EOF及相应的时间系数的年际变化分析表明,北半球冬季1月份500 hPa高度距平场高空流场中存在太平洋北美型（PNA）、太平洋西部型（WP）、大西洋东部型（EA）、欧亚西部型（EU）等遥相关型;夏季7月份存在西大西洋型（WA）、欧亚型（EU）、西太平洋型（WP）、极地东西遥相关型（PEW）、东亚太平洋型（EAP）、北美东西遥相关型（NAEW）等遥相关型。遥相关型的年际变化都非常明显,从时间系数序列可以看出,1948~2005年PNA型在冬季十分明显,在1977年前大部分年都是正相关,1977年后是负相关。而夏季则是EAP型比较明显,1978年是正负相关的分界点,夏季PNA型不出现。The 500 hPa height field in January in winter and July in summer in the north hemisphere from 1948 to 2005 was analyzed in this paper by dint of the estimates of spatial degrees of freedom and EOF significant examination method.And using the first ten eigenvalue and corresponding EOF,significance test was carried out.Results suggested that in January,the first eight EOF were relatively outstanding,while in July,the first nine EOF were quite significant.Analysis about the first four EOF in winter and summer and the annual variation of corresponding temporal coefficient suggested that the 500 hPa height anomaly height fluid in January in the northern hemisphere had different types of teleconnection such as PNA,WP,EA and EU etc.WA,EU,WP,PEW,EAP and NAEW existed in July.The annual variation of teleconnection was very obvious.Seen from temporal coefficient sequence,the PNA was outstanding in winter from 1948 to 2005,of which in most years before 1977 was positive correlation,while after 1977 was negative correlation.While in summer,EAP was relatively distinct and 1978 was the border point of positive and negative correlation.And PNA in summer didn＇t appear.

关 键 词：500hPa 空间自由度 EOF显著性检验 遥相关 

分 类 号：P434[天文地球—大气科学及气象学]