The influence of photochemistry on gravity waves in the middle atmosphere

Abstract

This paper focuses on the effect of diabatic processes due to photochemical heating on long-period gravity waves in the stratosphere, mesosphere and lower thermosphere. A linear diabatic gravity wave model is established and compared to a model of pure dynamical adiabatic gravity waves. The results indicate that the photochemistry has a damping effect on gravity waves in most regions of the stratosphere and mesosphere. However, the photochemistry has a destabilizing effect on gravity waves in the mesopause region. The photochemical heating process can induce a comparatively strong enhancement of gravity waves at the mesopause for lower temperatures. In the summer polar mesopause region, this growth rate may be greater by about one order of magnitude than the growth rate of gravity waves at other seasons and locations.