National Marine Environmental Forecasting Center Ministry of Natural Resources Beijing 100081 ChinaKey Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting Center Beijing 100081 China;
LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 ChinaUniversity of Chinese Academy of Sciences Beijing 100049 China;
Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China;
tropical Indian Ocean; El Niño prediction; sensitive area; targeted observation;