Instability Dynamics and Turbulent Mixing Efficiency from 3-D Direct Numerical Simulations of Gravity Wave Packet Breaking in A Mesopause Inversion Layer

In this presentation, we will show results of two 3-D direct numerical simulations (for shorter and longer gravity wave vertical wavelengths) of the propagation of a gravity wave packet into a representative mesospheric inversion layer (MIL) using a anelastic model. The wave packets exhibit strong instabilities when they encounter the MIL and the MIL flows become strongly turbulent. We will show the instability characteristics in some detail to document that the instability dynamics and transitions to turbulence are are well characterized. The resulting turbulent heat fluxes will also be reported and the implications for the turbulent mixing efficiency will be discussed.