摘要
本文用 Ansell 方法确定的10个厄尼诺年和6个反厄尼诺年分别计算了这两组年份前年、同年、次年各月,季的太平洋海温正距平和北半球500hPa 高度负距平出现的概率。并用北半球500hPa 高度场选取因子建立了秋季厄尼诺指数的预报方程,效果较好。
In this paper,the probabilities of both the positive departure of sea surface temperature(SST)at the Pacific Ocean and the negative geopot- ential departure in 500 hPa of the Northern Hemisphere in month and season from last to next year were computed for ten E1-Nio years and six anti-El-Nio years,which were defined by Ansell.It is evident that the main characteristics of the SST and the geopotential height in each season during the same period are contrary between El-Nio year and anti-El-Nio year.The life cycle for either El-Nio or anti-El-Nio can be divided into seven stages,i.e.portent,occurrence,development, prosperity,stability,weakness and extinction stages.There exists an opposite PNA teleconnection pattern in 500 hPa between them on the evolution of the circulation type,and there is the factor of change to- ward the opposite direction as they are happened.The representative season and district of El-Nio were defined objectively.The spectral analysis for the indexes of both El-Nio and PNA shows that the most obvious evidence is 42-month periodic variation,the index of El-Nio is backward for 4.15 months compared with that of PNA.On the other hand,the predictive equation for the El-Nio index in autumn is esta- blished by these predictors selected by the 500 hPa geopotential height of the Northern Hemisphere.The effect is satisfactory.
出处
《地理科学》
CSSCI
CSCD
北大核心
1991年第3期269-278,共10页
Scientia Geographica Sinica
基金
国家气象局长期预报课题组资助
关键词
厄尼诺
生命史
预测
遥相关型
El-nio
Life cycle
Forecast
PNA teleconnection pattern
