关键词: 中尺度模式, 湍流参数化, 能量闭合

Abstract: The improvement to the turbulence parameterization of meso-scale forecast model MM4 was presented. A turbulent kinematic energy(TKE)parameterization is used all over the forecast time in the whole model region to take the local K-theory's place in the bulk aerodynamic parameterization of the host model MM4, while MM4 with the high-resolution PBL parameterization is used as control forecast. MM4 with different parameterizations was utilized on the forecast of rainstorm on July 17, 1997, and new TKE parameterization introduced a reasonable distribution of turbulent variables. The computational stability is good and the forecast results of different variables are close to or better than those of the control model, Although locations of the strongest rainfall do not show any improvement, the amount of the 24-hour rainfall is larger than that forecasted by the control model. This amount is still not as large as the actual rainfall, but this result shows that the TKE parameterization is encouraging. The application of TKE parameterization readjusts the distribution of eddy viscosity, K_m, and hence improves the model.

Key words: meso-scale model, turbulence parameterization, turbulence kinematic energy