Eddy diffusion models for the mesosphere and lower thermosphere

Two-dimensional eddy diffusion around mesopause heights is modeled by means of a set of parameters relating eddy transports to average fields of meteorological quantities like wind variance and potential temperature. The so-called K-theory approach is used. The models in their present state have been used to study a few problems associated with the climatological behavior of the mesosphere and lower thermosphere: the relative importance of convective and eddy transports, implications of the mean winter anomaly of ionospheric absorption, the problem of strong mean vertical winds near the mesopause and the formation of the NO density minimum around 85 km altitude.