Parametrization of momentum and energy depositions from gravity waves generated by tropospheric hydrodynamic sources

摘要

The mechanism of generation of internalgravity waves (IGW) by mesoscale turbulence in the troposphere is considered.The equations that describe the generation of waves by hydrodynamic sources ofmomentum, heat and mass are derived. Calculations of amplitudes, wave energyfluxes, turbulent viscosities, and accelerations of the mean flow caused by IGWsgenerated in the troposphere are made. A comparison of different mechanisms ofturbulence production in the atmosphere by IGWs shows that the nonlineardestruction of a primary IGW into a spectrum of secondary waves may provideadditional dissipation of nonsaturated stable waves. The mean wind increasesboth the effectiveness of generation and dissipation of IGWs propagating in thedirection of the wind. Competition of both effects may lead to the dominance ofIGWs propagating upstream at long distances from tropospheric wave sources, andto the formation of eastward wave accelerations in summer and westwardaccelerations in winter near the mesopause.