Assessment of convective parametrization schemes over the Indian subcontinent using a regional climate model

An effort is made to investigate the performance of convective parameterization schemes on the simulation of characteristic features of monsoon rainfall over the Indian subcontinent using a regional climate model (RegCM). The sensitivity experiments with seven different convective parameterization schemes (CPSs) are carried out for this purpose. The simulated precipitation, temperature and wind fields are compared against the available observations and reanalysis dataset. The sensitivity experiments using "Grell" and "Massachusetts Institute of Technology over land and Grell over ocean (MLGO)" CPS show better performance in the simulation of precipitation, near-surface air temperature and circulation pattern over India as compared to the experiments using other CPSs. A systematic dry bias is seen in the simulations of summer monsoon rainfall in all the experiments, but the magnitude of the bias is lowest in the MLGO experiment. The Grell and MLGO experiments also show better performance in the simulation of seasonal cycle of summer monsoon rainfall. The relative performance of CPSs in simulating the vertical structure of temperature anomaly, relative vorticity anomaly and divergence anomaly associated with the summer monsoon rainfall over the Central Indian region is also investigated.