DISSIPATION OF WAVE DRAG IN THE ATMOSPHERIC BOUNDARY-LAYER

A simple parameterization of turbulence in an analytical study of wave drag (WD) is used upon governing equations for linearized, parallel, adiabatic, dry Boussinesq flow. Besides the known dependencies of WD o n vertical profiles of the mean wind and temperature and the shape of orographic disturbance, WD also depends on eddy diffusivity, which par ameterizes turbulence. Since eddy diffusivity is present, WD is not co nstant with height but is continuously dissipated in the atmospheric b oundary layer (ABL). This dissipation is sometimes not negligible beca use characteristic wavelengths associated with an ABL over small ridge s are short enough (lambda(x) approximately 1 km) to experience overal l turbulence. Under certain conditions and when no critical level is e ncountered (although critical level might be approached asymptotically here), WD can be reduced for roughly 15%-20% of its surface value. He nce, it is revealed that dissipation of WD can support turbulence in t he stable ABL.