Energetics of the Middle Atmosphere.
In this study, the middle atmosphere is considered to be the region from 25 to 105 km, including the middle and upper stratosphere, mesosphere, and mesosphere-thermosphere transition region up to the turbopause. Up to 80 km, energy inputs and losses are predominantly due to absorption and emission of radiation by ozone, carbon dioxide, and water vapor, with solar absorption by ozone and emission by carbon dioxide as major factors. Recent computations of heating and cooling rates due to these gases have not differed essentially from those previously calculated, but uncertainties remain primarily because of unresolved problems in the concentrations of water vapor and ozone. Above 80 km, nonradiative processes begin to play a major role. Kinetic energy transport associated with gravity waves, tidal waves, and Rossby waves appears to dominate the dynamics and may contribute significantly to heat input through dissipation. Although radiative processes continue to play a role, this region is much farther from radiative equilibrium than the region below 80 km. 30 pp. Ref.