Sensitivity Study with Physical Parameterization Sc hemes for Simulation of Mesoscale Convective Systems Associated with Squall Events

Abstract

Improving the simulation of the Pre-monsoon squall events is important as such events routinely result in strong gusty wind, hails, rain and significant loss of life and property over Bang ladesh, Indian eastern, northeastern region and neighborhood. Performance of the mesoscale models is sensitive to the physical parameterizatio ns schemes. This study deals the improvement of numerical simulation of sq uall events during pre- monsoon season through parameterizations. Advanced Research Weather Research and Forecasting model (WRF ARW) is used to improve the simulation of squall events. Several sensitivity ex periments were conducted with different combinations of cloud microphysics s chemes (MPSs) (namely; Lin, WSM3, WSM6 and Milbrandt), planetary boundary layer (PBL) schemes (namely; YSU, MYJ and ACM2) and cumulus (CU) parameterization schemes (namely; Kain-Fritsch, Betts-Miller-Janji c, Grell- Devenyi and no-cumulus), to examine the root mean square errors (RMSE) of rainfall, wind speed at 10 m and forecast time. In particular, the combination of Milbrandt and WSM6 microphysics scheme with Yonsei University (YSU) PBL scheme and no CU scheme provides optimal combination of physical parameterization schemes in simulation of the squall events.