Modulation of MJO-diurnal cycle interaction over the Maritime Continent
Recent studies show that, via non-linear interactions between cloud processes and surface fluxes, diurnal cycle over the Maritime Continent (MC) islands can weaken and stall propagating MJO convection signals. In this work, the processes that modulate this non-linear interaction are investigated in order to understand why some events of the MJO cross the MC and others do not. New high-resolution precipitation data from passive microwave (PMW) sensors and surface and sounding data from the Maritime Continent are used to extensively document the diurnal cycle of precipitation as well as surface and atmospheric environmental conditions over and around the major islands of the MC before the arrival of the MJO events. Regional cloud permitting model simulations of propagating and disrupted MJO events are then used to test hypotheses derived from the observations. This is done by swapping initial land surface and lateral atmospheric conditions between the model simulated MJO events that successfully cross the MC and those that were disrupted. Results of this study will be discussed in the context of the planned YMC/PISTON field campaigns.