2015-16 floods and droughts in China, and its response to the strong El Nino

摘要

The features of hydro-climate anomalies in China in 2015–2016 were analyzed in great detail, together with possible responses to the super 2015–16 El Niño event. The 2015–16 El Niño is characterized as a “strong” event in terms of the duration, intensity, and coverage of warming sea surface temperature (SST) in the central and east-central equatorial Pacific in comparison to the 1982–83 and 1997–98 events. The floods and droughts frequency were incidence of floods and droughts per year, respectively. The results show several significant anomalies in China: 1) About 9%–173% of precipitation variance in 2015–16 can be attributed to this El Niño; 2) There was significant inconformity between hydro-climate anomalies and the occurrence of floods and droughts; 3) Flood frequency has increased, especially over Southeast China and the Yangtze River in the summer of 2016; 4) Drought frequency has also increased, especially over Northeast China in summer of 2015, Northwest China in spring of 2016, and most parts in winter of 2015. The response of China hydro-climate anomalies to the 2015–16 El Niño was significant via El Niño and warm Indian Ocean induced circulation anomalies, which were characterized by stronger and more westward-extending western Pacific subtropical high and anomalous water vapor transport. Knowledge of the response of hydro-climate extremes to El Niño can provide valuable information to improve flood and drought forecasting in China.