Characteristics of Atmospheric Circulation over the Middle and Lower Reaches of Yangtze River in Midsummer 2015 and Impact of ENSO
The atmospheric circulation for the low temperature in the middle and lower reaches of the Yangtze River in midsumer 2015 and the possible impact of the 2015/2016 El Ni〖AKn~D〗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 circulation 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 River. El Ni〖AKn~D〗o developed rapidly in the summer of 2015, which might be the possible main reason for the Eurasian atmospheric circulation anomalies in the midsummer of 2015.