Mesospheric Sodium Airglow Emission: Modeling and Firstresults Over a Mid-Latitude

Atmospheric sodium plays a very important role in the mesospheric chemistry and dynam-ics. We have developed a comprehensive model for mesospheric/thermospheric sodium airglowemission by incorporating all the known reaction mechanisms. The latest reaction rate coeffi-cients and the related cross sections are obtained from the theoretical studies and experimentalobservations. The continuity equations are explicitly solved for the major species. Similarly, thesteady-state approximation has been used for the intermediate and short lived minor species.The number densities from in-situ observations, NRLMSISE-00, and IRI-2012 have been suc-cessfully implemented to calculate the vertical volume emission rate. The modeled resultscompared to a good agreement with the measured profiles of Na airglow emission. The meso-spheric sodium density shows a large day-to-day variability. The observed variations in themesospheric sodium layer have been incorporated to obtain the variations in the sodium air-glow intensities. The nocturnal variation of sodium airglow emissions are presented over a midlatitude location using this model.