Turbulence in broken lee waves

In this paper, the waves' breaking in the lee waves in successfully simulated by the atmospheric mesoscale numerical model with a second-order turbulent closure. It is further proved that the turbulence in the wave-breaking region plays the role of intense mixing for the average field, which leads to the trapping of upward propagating waves and thus promotes the development of the downslope wind. The turbulent structure in the wave-breaking region is discussed and the following conclusions are obtained: (1) In the wave-breaking region, the turbulent heat fluxes transfer from inside to outside and the turbulent momentum fluxes transfer from outside to inside. (2) In the wave-breaking region, the turbulent energy mainly comes from the wind shear and the buoyancy promotes the turbulent development only in part of the region. (3) In the upper part of the wave-breaking region, the turbulent momentum fluxes behave as a counter-gradient transfer. (4) The turbulent mixing in the wave-breaking region is non-local. recommended by Professor Li Jiachun.