Vibrational populations of the excited states of N_{2} under auroral conditions
Abstract
The equations of statistical equilibrium for the population and depopulation of the electronic states of N_{2} have been solved for steady state normal auroral conditions. All vibrational levels for the seven lowest triplet electronic states (A, B, W, B', C E, D) and the three lowest excited singlet electronic states (a, a', w) of N_{2} were included in the calculations. Recently mesured auroral secondary electron spectra were employed to calculate the rates for electron impact excitation. The transition probabilities, electron impact excitation cross sections, and vibrationally dependent quenching rates used were a combination of the best available experiment and theoretical data. The results of these calculations are the absolute vibrational populations of all the electronic states. Intrasystem cascading and vibrationally dependent quenching were found to be important in determining the vibrational populations in the lower singlet and triplet excited electronic states. The predicted vibrational populations for the A and B triplet states agree well with the available experiment data. These calculations predict that a fairly large density of N_{2} in excited metastable states in produced under auroral conditions.
 Publication:

Journal of Geophysical Research
 Pub Date:
 February 1978
 DOI:
 10.1029/JA083iA02p00517
 Bibcode:
 1978JGR....83..517C
 Keywords:

 Atmospheric Chemistry;
 Auroral Spectroscopy;
 Molecular Energy Levels;
 Molecular Excitation;
 Nitrogen;
 Vibrational Spectra;
 Diatomic Gases;
 Electron Impact;
 Electron Spectroscopy;
 Transition Probabilities;
 Geophysics