Abstract:In this study,targeted at the uncertainty in the parameterization process of the planetary boundary layer in the WRF model,a Stochastic Perturbation on Planetary Boundary Layer Parameterization Tendency scheme (SPPBLPT) was developed.This scheme perturbs the temperature,wind and water vapor tendencies.A comparative experiment was conducted in July 2014 using the SPPBLPT scheme,multi-planet boundary layer parameterization scheme,multi-parameter perturbation scheme,and Stochastic Physical Process Perturbation (SPPT) scheme.It was observed that the SPPBLPT scheme with a large grid-point variance can effectively reduce the error of 2 m temperature and wind field,and it can also reduce precipitation error,while other schemes do not improve the forecast significantly.The BS scores for the 2 m temperature and wind field show that the SPPBLPT scheme significantly improves the possibility of ensemble forecasting for temperature and wind field,by reducing the reliability score,thereby increasing performance.At the same time,the scheme can significantly improve the GSS score of the precipitation.In all experiments,the SPPBLPT scheme with the larger grid-point variance had a superior performance.Although the SPPBLPT scheme reduced the FSS score,the reduction was not significant.It is thus shown that the SPPBLPT scheme can significantly improve the performance of ensemble forecasting systems,yet the setting of perturbation parameters for this scheme requires further investigation.