Synoptic-Scale Modulation of Convection during the Australian Summer Monsoon

Abstract

Abstract Time-longitude representations of Japanese Geostationary Meteorology Satellite (GMS) infrared imagery indicate the existence of major synoptic-scale banding of convection within the Australian summer monsoon. This bands can be interpreted as active and break phases of major convective activity within the monsoon. This study relates the occurrence of convection and its organization into synoptic-scale bands to observable flow features. GMS Digital Equivalent Blackbody Temperature (TBB) data and wind fields from the Australian Numerical Meteorology Research Centre (ANMRC) tropical analysis scheme for the 1978/79 and 1983/84 seasons were composited relative to wind field surges and bands of enhanced and suppressed convective activity. Some low-level wind surges in the South China Sea produced a modulation in the convective activity within the preexisting bands but did not seem to be associated with their formation. Surges in the Southern Hemisphere trade-wind easterlies and the southerly jet off the...