A model calculation of the diurnal variation in minor neutral constituents in the mesosphere and lower thermosphere including transport effects

摘要: The nonequilibrium calculation for various neutral constituents in the mesosphere and lower thermosphere (Hunt, 1966) was extended by including effects of molecular eddy diffusion. Nitrogen its oxides were added, more recent laboratory data chemical reaction coefficients used. A special numerical technique has been developed to simultaneously solve time-dependent continuity equations 14 constituents. preliminary result indicates that vertical diffusion significantly reduces irregular variations around 80 km tends height these variations. However, value coefficient acceptable from consideration heat balance below ∼100 cannot entirely smooth out distributions atomic oxygen, ozone, oxygen-hydrogen compounds, although smoothing effect nitric oxide seems be strong enough eliminate above ∼70 km. role transport terms equation is illustrated explicitly discussed some representative cases. We show dynamic model fits observational results ozone concentrations better than static also offers a adequate explanation observed diurnal variation OH airglow emission.