The physics of orographic gravity wave drag
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چکیده
*Correspondence: Miguel A. C. Teixeira, Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, UK e-mail: [email protected] The drag and momentum fluxes produced by gravity waves generated in flow over orography are reviewed, focusing on adiabatic conditions without phase transitions or radiation effects, and steady mean incoming flow. The orographic gravity wave drag is first introduced in its simplest possible form, for inviscid, linearized, non-rotating flow with the Boussinesq and hydrostatic approximations, and constant wind and static stability. Subsequently, the contributions made by previous authors (primarily using theory and numerical simulations) to elucidate how the drag is affected by additional physical processes are surveyed. These include the effect of orography anisotropy, vertical wind shear, total and partial critical levels, vertical wave reflection and resonance, non-hydrostatic effects and trapped lee waves, rotation and nonlinearity. Frictional and boundary layer effects are also briefly mentioned. A better understanding of all of these aspects is important for guiding the improvement of drag parametrization schemes.
منابع مشابه
Turbulent transport and interactions with the surface Chapter 4 Subgrid - scale orographic drag Chapter 5 Non - orographic gravity wave drag
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تاریخ انتشار 2014