Development of atmospheric turbulence models on the Complex Terrain and its application to the Atmospheric impact assessment

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The present study systematically compared the MY model and KEASM and verified the possibility of using KEASM for atmospheric application. The results of the parameterization process of both models and the simulation of the Wangara experiment are as follows : (1) The MY model neglects the redistribution effects of buoyancy due to <μi, μj> andμ<μi, θ> and of shear due to <μi, θ>. Subsequently, the MY model does not agree with the observed data of Businger in the unstable condition (ζ<0) for φ_M, and largely evaluates the stability function for momentum as compared to the modified MY model and KEASM. In addition, we were able to verify that the eddy coefficients for momentum and heat are to a large degree affected by the turbulent length scale or the turbulent energy dissipation, rather than the closure model assumptions. Consequently, the MY model overestimated the turbulent energy dissipation and yielded a very low evaluation of PBL height for the simulation of the Wangara experiment. (2) KEASM includes the pressure redistribution effects due to the ground, as well as those of buoyancy due to <μiμj> and <μiθ> and of shear due to <μiθ> . KEASM is in good agreement with the data observed by Businger, particularly for turbulent Prandtl number. In addition, we were able to verify that KEASM modifies the constant C_μ of SKEM to be a function of the flux Richardson number as well as the possibility of using KEASM for atmospheric application.