'Scale Interactions in the Tropics from a Simple Multi-cloud Model'

The limited understanding of tropical meteorology, especially of the interaction between the moisture convection and equatorial waves, has blocked the current climate model to simulate and forecast the Madden-Julian Oscillation (MJO). The reported research project focuses on investigating the non-linear interaction between a variety of convective forcing patterns in the equatorial region and the development as well as the transportation of tropical convection systems along with the equatorial waves, ranged in different scales, using a simplified multi-cloud model. The multi-cloud model^[1] is developed on the synoptic-scale equatorial primitive equations and embedded with a convection parameterization that based on the main three cloud types: congestus, deep, and stratifrom that are observed to play an important role in the dynamics of tropical convective systems. The multi-cloud is simplified in this project by reserving the essential physical processes and eliminating or modifying the unnecessary parameterizations. The simplified multi-cloud has been developed and its sensibility of the parameters involved is being tested. A series of ideal numerical experiments with a variety of convective forcing patterns will be performed and the results, including the wave activity of the moist-coupled equatorial wave as well as the upscale fluxes generated by it will be analyzed, in the future study.

[1] Khouider, B., & Majda, A. J. 2016: Models for Multiscale Interactions. Part I: A Multicloud Model Parameterization. Meteorological Monographs, 56, 9-1.