Modelling isolated wave-turbulence interactions in the stable atmospheric boundary layer

The interaction between a large-scale isolated wave and turbulence is considered in the context of the stable atmospheric boundary layer. A two-dimensional model with a second-moment turbulence closure is used to simulate the interaction numerically. Results obtained using other closures are discussed. the initial form of the wave-like disturbance is suggested by observations, which are described in a companion paper. the turbulence is shown to exert only a small influence on the wave, while the turbulence itself remains close to production-dissipation equilibrium. Wave-like components of the turbulence fluxes vary roughly linearly with wave amplitude, but overall the wave is strongly nonlinear and depends heavily on the background flow. Only one term in the equations for the quadratic turbulence quantities varies in a simple way with wave amplitude; this term represents a net transfer of energy from the wave to the turbulence.

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