Development Characteristics and Dynamic Structure of Tropical Intraseasonal Convection Anomalies

摘要: Abstract The development and dynamical structure of intraseasonal low-frequency convection anomalies in the equatorial region are investigated using 10 years (1975–85) outgoing longwave radiation (OLR) 7 (1979–85) 200 850 mb wind data. composite OLR for 36 cases show a four-stage process: initiation over Africa, rapid intensification when passing through Indian Ocean, mature evolution characterized by weakening maritime continent redevelopment western Pacific, dissipation near date line moderate events or emanation from equator toward North America southeastern Pacific strong events. A noticeable feature vertical is that convergence leads midtropospheric upward motion about 30 degrees longitude both developing phases. Equatorial upper- (lower-) level easterly (westerly) associated twin anomalous anticyclonic (cyclonic) circulation an...