Multi-timescale variability of tropical convection in the Indo-western Pacific Ocean

Abstract

The convective activity is one of the most important features of the tropics, which is closely related to climate variability on multiple time scales. Observational evidence of the coexistence of different time scales in the variation of tropical convective activity was presented in previous studies. This paper mainly reviews the recent progress of variability of convective system over the Indo-western Pacific sector on diurnal, synoptic, intraseasonal, interannual, and decadal-interdecadal time scales, as well as the associated physical processes. The interannual variability of tropical convective activity is strongly modulated by the anomalous large-scale Walker circulation, which is tied to ENSO event. Periodical intraseasonal oscillations in convection are the prominent feature in the tropical Indo-western Pacific Ocean. The tropical cyclones and monsoonal precipitation occurred at the equator and off-equator are closely linked to the synoptic-scale variation of convective activity, northward- and northwestward-propagating intraseasonal oscillation of convection in the Asian monsoon region during boreal summer. The impact of anomalous tropical convective system and associated large-scale circulation on climate variability is of great importance to surrounding countries in the Asian summer monsoon region.