A Contrastive Study Of Numerical Experiments Of Different Boundary Layer Parameterization

With the improvement of the model simulation requirements, parameterization of physical processes in the coupled climate model simulation will be more and more important. Improvement and development of the parameterization scheme of the key physical processes in climate models, and the coupled model of climate change simulation skills and abilities, will be one of the primary solutions of the key scientific issues. Which the boundary layer parameterization is an important part; there are certain problems but the current parameterization scheme. Therefore, the analysis of the problems within the boundary layer closure program and their applicability is very necessary. By analyzing the performance of different turbulence closure model in the same model, we will find the difference between these closure parameterization schemes. And it will provide a reference to select the appropriate parameterization scheme. Then the forecast effect of the mode will be improved.At the same time, the application of a turbulence closure model is dependent on the numerical process. The finite element method is an effective numerical analysis. Engineering and many disciplines have wide applications in atmospheric numerical simulation.In this paper, we will develop a planetary boundary layer parameterization scheme, the model includes not only the process of planetary boundary layer, also includes the land surface process, long and shortwave radiative transfer process and the turbulence transmission with low-level cloud interactions and other important physical processes, finite element analysis method to improve the process of numerical calculation, the performance of different turbulence closure model in the simulation of the Wangara experiment33days of the development process of the planetary boundary layer analysis of the problems of different parameterization schemes. Then the model will be used in Inner Mongolia semi-arid regions tested, designed to test the model performance.The results show that the model developed in this paper is good at simulating boundary layer, and it is better than the finite difference model. Simulation of the daytime convective boundary layer shows that, the first-order closure mode is basically simulate the temperature variation, but not precise enough, the second-order closure model simulations improved and better than the finite difference model; first-order closure model can simulate the vertical distribution of specific humidity, the value of second-order closure model to simulate the wet than the measured value of specific humidity; the both models could simulate the wind speed variation of the second-order error is smaller; the second order closure model has some improvements in simulating the heat flux simulation; an order of the simulated boundary layer height is greater than the measured height of200meters, the second-order closure model simulation results and the measured results is very consistent; first-order closure model to simulate the turbulent kinetic energy above the second-order nearly a one-third of the part, and slightly behind in phase second-order closure model simulations. The model results are roughly the same. The simulation of the nocturnal stable boundary layer shows that, the simulation of the first-order closure model temperature results in addition to the SBL upper part differently, the simulation results and measured results is more consistent; second-order simulation accuracy is good than the first-order improvement simulation result; first-order closure mode can simulate the trend of wind speed and low-level jet, but the deviation is still large; the second-order closure model has some improvements in simulating the SBL height, but the results is less than the measured value; the second order closure model can simulate the top of the SBL, the result is consistent with the observed facts; the second-order closure model simulates the three components of turbulent kinetic energy in turbulent mixing in the lower part of the SBL, and make them remain constant in different height.