长江中下游2015年盛夏低温的大气环流特征及ENSO的影响

摘要

利用NCEP再分析资料和ERSST资料分析了长江中下游2015年盛夏低温的大气环流特征,并探讨2015/2016年厄尔尼诺事件的可能影响.研究表明:长江中下游2015年盛夏气温为1961年以来第二低.造成长江中下游低温的直接原因是2015年盛夏欧亚大气环流异常稳定,在亚洲地区表现亚洲北部阻塞高压与东亚低槽形成的偶极子形势,导致冷空气不断南下影响到长江中下游地区;而2015年夏季厄尔尼诺快速发展可能是2015年盛夏欧亚大气环流异常的主要原因.%The atmospheric circulation for the low temperature in the middle and lower reaches of the Yan-gtze River in midsumer 2015 and the possible impact of the 2015/2016 El Ni?o event are analyzed by using NCEP reanalysis data and ERSST data.The results show that the 2015 midsummer mean temperature was lower than normal,which ranks the second lowest since 1961.The direct cause of the low temperature in the middle and lower reaches of the Yangtze River was the abnormal consistent Eurasian atmospheric circu-lation in midsummer of 2015.In the Asian Region,the dipole pattern of the blocking over north Asia and the low trough over East Asia led to the cold air affecting the middle and lower reaches of the Yangtze Riv-er.El Ni?no developed rapidly in the summer of 2015,which might be the possible main reason for the Eur-asian atmospheric circulation anomalies in the midsummer of 2015.