EXPERIMENT ON THE FORECAST OF CHARACTERISTIC QUANTITIES OF ATMOSPHERIC TURBULENCE BY MESOSCALE MODEL MM5^*

In nested nonhydrostatic mesoscale model MM5,the characteristic quantities of atmospheric turbulence,i.e.,the standard deviations of the turbulent fluctuated speeds for three directions in PBL are computed by Mellor-Yamada's level 2.5 closure scheme.The magnitudes and the vertical profiles of these quantities computed from the model are closely connected with temperature and wind speed profiles as well as the type of the ground with a significant diurnal variation,and are in agreement with known magnitudes and regularities in different stratification conditions.Hence the method in this paper is reasonable and convincible.Their horizontal distribution depends on the horizontal distribution of the stratification.The method of predicted characteristic quantities of turbulence from mesoscale model in this paper can be used in the problem of atmospheric diffusion and atmospheric environment.