A one-dimensional model for minor neutral constituents in the mesosphere and lower thermosphere

154-165A time dependent one-dimensional model for the middle atmospheric minor neutral constituents of aeronomic interest is worked out. The model considers transport only in the vertical direction and calculates the vertical distributions of the minor neutral constituents in the altitude range 60-120 km, at intervals of 2 km, for specified solar and terrestrial conditions. These conditions are specified through (i) the solar radiation fluxes in 120 wavelength bands in the range 116.3-435.0 nm, (ii) the solar zenith angle and vertical distributions of temperature,(iii) eddy diffusion coefficient and (iv) the number densities of O2 and N2 in the atmosphere. Model derived results for solar minimum conditions, characterized by a sunspot number of 20 and for a solar zenith angle of 30° at low latitudes, are presented. The results are representative of noontime annual mean values for a latitude of 11°N and are discussed in the light of similar model results and observations reported earlier

One- and Two-Dimensional Models for Middle Atmospheric Minor Constituents

220-231The salient features of formulation of one- and two-dimensional models are briefly reviewed. The details of a one dimensional model developed and the results obtained from this model are presented and discussed. The results obtained from different two-dimensional models are also discussed