The combined effects of the ENSO and the Arctic Oscillation on the winter climate anomalies in East Asia  

作　　者：CHEN Wen LAN XiaoQing WANG Lin MA Yin 

机构地区：[1]Center for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2013年第12期1355-1362,共8页

基　　金：supported by the National Basic Research Program of China (2009CB421405);the National Natural Science Foundation of China (41025017 and 41230527)

摘　　要：With the warm/cold phases of the El Ni o and Southern Oscillation (ENSO) as a background, the impacts of monthly variation in the Arctic Oscillation (AO) on the winter climate anomalies in East Asia are studied with the NCEP/DOE Reanalysis 2 data and the Chinese station data regarding temperature and rainfall. The combined effects of ENSO and the AO indicate that the winter climate anomalies are mainly influenced by the AO in northern China and the ENSO in southern China, when an El Ni o couples with a negative AO month or a La Ni a couples with a positive AO month. These climate anomalies in China are consistent with the mechanisms proposed in previous studies. However, most of China presents a different pattern of climate anomalies if an El Ni o couples with a positive AO month or a La Ni a couples with a negative AO month, with the exception of the temperature anomalies in northern China, which are still affected dominantly by the AO. Further analysis suggests that the causes are attributed to the differences in both the stratosphere-troposphere interaction and the extratropics-tropics interaction. In the former cases, zonal symmetric circulation prevails in the winter and the extratropics-tropics interaction is weakened. Thus, the influences of the ENSO and the AO on the East Asian climate mainly present linear combination effects. On the contrary, an annular mode of atmospheric circulation is not favored in the latter cases and the extratropics-tropics interaction is strong. Hence, the combined effects of the ENSO and the AO on the winter climate in East Asia present nonlinear characteristics.With the warm/cold phases of the El Nifio and Southern Oscillation （ENSO） as a background, the impacts of monthly variation in the Arctic Oscillation （AO） on the winter climate anomalies in East Asia are studied with the NCEP/DOE Reanalysis 2 data and the Chinese station data regarding temperature and rainfall. The combined effects of ENSO and the AO indicate that the winter climate anomalies are mainly influenced by the AO in northern China and the ENSO in southern China, when an El Nifio couples with a negative AO month or a La Nifia couples with a positive AO month. These climate anomalies in China are consistent with the mechanisms proposed in previous studies. However, most of China presents a different pattern of climate anomalies if an El Nifio couples with a positive AO month or a La Nina couples with a negative AO month, with the exception of the temperature anomalies in northern China, which are still affected dominantly by the AO. Further analysis suggests that the causes are attributed to the differences in both the stratosphere-troposphere interaction and the extratropics-tropics interaction. In the former cases, zonal symmetric circulation prevails in the winter and the extratropics-tropics interaction is weakened. Thus, the influences of the ENSO and the AO on the East Asian climate mainly present linear combination effects. On the contrary, an annular mode of atmospheric circulation is not favored in the latter cases and the extratropics-tropics interaction is strong. Hence, the combined elfects of the ENSO and the AO on the winter climate in East Asia present nonlinear characteristics.

关 键 词：气候异常变化 ENSO事件 冬季气候 东亚气候 北极涛动 大气环流模式 中国南部 中国北方地区 

分 类 号：P461[天文地球—大气科学及气象学]