Research And Application Of The Cumulus Parameterization Scheme In Numerical Weather Prediction Model

This paper studies the application of cumulus convection parameterization scheme based on the global atmospheric hydrostatic spectral model.The parameterization of physical processes has an important influence on the prediction results of numerical model.It not only describes the physical mechanism of cumulus convection and convective precipitation,but also feeds back the predicted influence on temperature field and water vapor field to the dynamic process.This paper studies the development and evolution of cumulus convective parameterization,and summarizes the main development of cumulus convection parameterization scheme.The BMJ scheme in WRF is introduced into the operational forecasting spectral model in order to further develop the cumulus convection parameterization scheme in the operational model by taking advantage of the convection adjustment in BMJ scheme.The BMJ scheme and the TDK scheme are studied from two aspects of theory and model application in this paper.This paper compares the BMJ scheme and the TDK scheme from the aspects of convection type judgment,different convection processing,scheme prediction variables and update variables,and combines the interface analysis in the numerical model to lay a foundation for introducing operational prediction spectral model into the BMJ scheme.By analyzing the existing parallel computing framework and data structure partition of operational prediction spectral model,this paper finds that the calculation of the parameterization of physical processes is only related in the vertical direction and has nothing to do with the gas column of horizontal grid.This paper theoretically solves the problem whether the BMJ scheme can introduce into operational prediction spectral model,and draws the conclusion that the BMJ scheme can adapt to the existing parallel framework of operational prediction spectral model.After sloving the problems of initialization,input variables,coordinate transformation and output variables,this paper successfully introduces the BMJ scheme into YHGSM.This paper selects a large-scale heavy rainfall process occurred in Southern China area of China from March 9 to 10,2017 as an experimental example to compare the forecasting results of the BMJ and TDK scheme.Finally,this paper tests and compares the potential height at 500 hPa,the temperature field at 850 hPa and the wind field at 500 hPa in the northern hemisphere of BMJ and TDK schemes in March 2017,by using the standardized test method of numerical forecast products.The results show that the prediction effect of BMJ scheme is comparable to that of TDK scheme,that is,the prediction effect of BMJ scheme is neutral.