The Role of Diurnal SST Variation and the Large-Scale Atmospheric Waves on the CINDY/DYNAMO Moist Resurgent Processes

The diurnal variability and the environmental conditions that support the initiation of three MJO events observed during the CINDY/DYNAMO campaign in October-December 2011 are investigated using in-situ observations and the cloud resolving fully air-ocean-wave Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPSŪ). Analyses of real data and idealized COAMPS forecasts suggest that local-air-sea interaction and horizontal and vertical moisture transport associated with the atmospheric large-scale waves play a non-negligible role in modulating the moisture increase prior to the CINDY/DYNAMO MJO initiation. In particular, the westward moving mixed Rossby-gravity waves were found to have a significant impact through the horizontal and vertical advection of moisture. We will discuss the use of model simulations to quantify these different contributions to the moisture resurgent processes. Observations supporting these model findings, as well as a hypothesized conceptual model, will be presented.