In this study,the monthly and seasonal teleconnection intensity indices of the Pacific/North American(PNA), Western Atlantic(WA),Western Pacific(WP),Eastern Atlantic(EA)and Eurasian(EU)patterns for the period from 195...In this study,the monthly and seasonal teleconnection intensity indices of the Pacific/North American(PNA), Western Atlantic(WA),Western Pacific(WP),Eastern Atlantic(EA)and Eurasian(EU)patterns for the period from 1951 through 1990 are calculated.On this basis,their climatic variations and the relationship between the five teleconnection intensity indices and the El Nino events are examined.It is noted that when El Nino is at its mature stage (winter),the weak WP pattern is mainly characteristic of the circulation and the strong PNA pattern is the next.In summer when El Nino occurs and develops,the strong EU,weak WP and weak WA patterns are the main characteris- tics without the PNA circulation anomalies.Finally,by the nonlinear mapping method a nonlinear mapping diagram is established for diagnosing El Nino using three summer teleeonuection intensity indices and May and August Southern Oscillation Indices(SOIs).Thus,the El Nino phenomenon occurring in 1991 is diagnosed.Besides,the winter atmos- pheric circulation of the 1991/1992 El Nino is found to be the weak WP pattern and the PNA pattern is also weak.展开更多
基金sponsored by the National Natural Science Foundation and Monsoon Research Funds
文摘In this study,the monthly and seasonal teleconnection intensity indices of the Pacific/North American(PNA), Western Atlantic(WA),Western Pacific(WP),Eastern Atlantic(EA)and Eurasian(EU)patterns for the period from 1951 through 1990 are calculated.On this basis,their climatic variations and the relationship between the five teleconnection intensity indices and the El Nino events are examined.It is noted that when El Nino is at its mature stage (winter),the weak WP pattern is mainly characteristic of the circulation and the strong PNA pattern is the next.In summer when El Nino occurs and develops,the strong EU,weak WP and weak WA patterns are the main characteris- tics without the PNA circulation anomalies.Finally,by the nonlinear mapping method a nonlinear mapping diagram is established for diagnosing El Nino using three summer teleeonuection intensity indices and May and August Southern Oscillation Indices(SOIs).Thus,the El Nino phenomenon occurring in 1991 is diagnosed.Besides,the winter atmos- pheric circulation of the 1991/1992 El Nino is found to be the weak WP pattern and the PNA pattern is also weak.
