摘要
In this paper, based on the 2°× 2° grid data COADS from 1950—1987 the flow field and heat exchange anomalies on the tropical (11°S—11°N, 120°E—80°W) Pacific surface (TPS) are studied in El Nino and La Nina events. During E1 Nino, the zonal pressure gradient and the trade winds decrease on the TPS, the tropical convergence strengthens on the TPS, especially on the central TPS, the sensible and latent heat exchanges increase, the net longwave radiation and incident solar radiation decrease and the net gain (loss) of heat reduces (increases) on the central and eastern TPS. During La Nina the results turn out the contrary. Finally, two feedback mechanisms which include the dynamic, thermal and hydrological processes during E1 Nino and La Nina are summa- rized and a conceptive model for El Nino-La Nina cycle is given.
In this paper, based on the 2°× 2° grid data COADS from 1950—1987 the flow field and heat exchange anomalies on the tropical (11°S—11°N, 120°E—80°W) Pacific surface (TPS) are studied in El Nino and La Nina events. During E1 Nino, the zonal pressure gradient and the trade winds decrease on the TPS, the tropical convergence strengthens on the TPS, especially on the central TPS, the sensible and latent heat exchanges increase, the net longwave radiation and incident solar radiation decrease and the net gain (loss) of heat reduces (increases) on the central and eastern TPS. During La Nina the results turn out the contrary. Finally, two feedback mechanisms which include the dynamic, thermal and hydrological processes during E1 Nino and La Nina are summa- rized and a conceptive model for El Nino-La Nina cycle is given.
