大气运动的动能在湍流边界层中的耗散

在大气能量学中,大气平均运动的动能通过湍流摩擦力转化为脉动运动的能量并最终转化为内能的“变性能量”是大气动能的“汇”,正确估计其大小对研究动能的收支,以至天气系统的生衰,发展均有一定意义。此项由于与湍流通量有关,因而难于从大尺度气象参数计算。以往的研究中,或是将动能平衡方程中其余各项算出,而将此项作为余项估计出,或用地转风由粗浅的边界层模式算出。

THE DISSIPATION OF THE ATMOSPHERICKINETIC ENERGY IN THE TURBULENTBOUNDARY LAYER

The dissipation of the kinetic energy caused by turbulent friction is difficult to be evaluated in atmospheric energetics. In this paper, based on the parameterization method in the modern boundary layer dynamics, a method for calculating the dissipation from the external parameters including geostrophic wind speed, the bulk stratification parameter for the boundary layer, the baroclinity parameters, the roughness of the ground and the Coriolis parameter is suggested, and the numerical results for the relations between the dissipation and these parameters are obtained, improving the knowledge about the dissipation of the kinetic energy. The methods in this paper can be applied in the large and mesoscale models to evaluate the disspation of the kinetic energy caused by the turbulent friction in the boundary layer.