A Study of the Scale-Aware Physical Parameterizations in High-Resolution Numerical Weather Prediction Models

The resolution of numerical weather prediction models will continually increase with increasing computer power. Physical processes parameterizations associated with convection, cloud and planetary boundary layer (PBL) depend on the resolutions of model. These motions can be partially resolved by grid scale dynamics. However, a substantial part of turbulent motion still needs to be parameterized, which results in the so-called gray zone problem. The gray zone problem can hugely downgrade the forecast skill of the numerical prediction models. In this study, a scale-aware subgrid mixing (including turbulence in PBL) scheme and a scale-aware cumulus convection scheme are developed. The new schemes will adapt to the model grid size as it is varied through the gray zone.This study will provide theoretical and technical supports for the development of high-resolution numerical weather model and operational prediction.