Simulation of Organized Convection and Tropical-wave Coupling in a YOTC MJO

Abstract:

Organized precipitating convection coupled to various tropical waves was impressively complex in the eastern Indian Ocean in the April 2009 MJO, one of the six MJOs that occurred during the YOTC virtual global field campaign (May 2008-April 2010). Organized convection in the form of a westward-propagating synoptic-scale supercluster and a family of eastward-propagating mesoscale squall lines formed west of Sumatra. The supercluster was strongly coupled to a westward inertio-gravity wave. All these features are embedded in an equatorial Rossby wave, and the MJO overall. The 1.3 km inner-grid of the WRF model, nested in a 4 km-grid outer-grid spanning the Indian Ocean and the western Maritime Continent region, successfully simulated the timing, location, propagation, and life-cycle of this multiscale convection-wave interaction as verified by TRMM measurements.