The Stokes Drift due to Vertically Propagating Internal Gravity Waves in a Compressible Atmosphere

Abstract

Vertically propagating, compressible, internal gravity waves are shown to have a vertical Stokes drift which is proportional to the vertical wave energy flux. In regions of the atmosphere dominated by upward propagating waves, such as the summer mesosphere, this Stokes drift will be upward. For the Lagrangian mean parcel motion to be small, a downward mean Eulerian velocity must exist to largely oppose the upward Stokes drift. These. results may explain the downward mean Eulerian velocity observed at Poker Flat, Alaska in the summer mesosphere.