A model for calculating acoustic gravity wave energy and momentum flux in the mesosphere from OH airglow

Abstract

Acoustic gravity and tidal waves propagating in the mesosphere/lower thermosphere (80-110 km) perturb the airglow layer intensities. The OH airglow has recently been modeled to determine the relationship between the relative perturbed atmospheric density and temperature ( ρ′/ρ, T′/T) to the OH intensity (I′OH/IOH) at the OH emission altitudes [Swenson and Gardner, 1997]. A model is presented here which relates wave perturbed OH airglow to the wave energy and momentum flux as they propagate through the emission layer. The model is dependent on the wave horizontal and vertical wavelengths (or phase speed as related through the dispersion relationship), and the relative perturbed airglow intensity, I′OH/IOH. The model can be used by optical experimenters to relate their measurements to wave energy and momentum flux in the stated altitude region.