The role of vibrationally excited oxygen and nitrogen in the D and E regions of the ionosphere

• Main Author: A. V. Pavlov
• Format: Article
• Language: English
• Published: Copernicus Publications
• Series: Annales Geophysicae
• Online Access: http://www.ann-geophys.net/12/1085/1994/angeo-12-1085-1994.html
• ISSN: 0992-7689; 1432-0576

In this paper we present the results of a study of the effect of vibrationally excited oxygen, O<sup>*</sup><sub>2</sub>, and nitrogen, N<sup>*</sup><sub>2</sub>, on the electron density, <i>N</i><sub>e</sub>, and the electron temperature, <i>T</i><sub>e</sub>, in the D and E regions. The sources of O<sup>*</sup><sub>2</sub> are O-atom recombination, the photodissociation of O<sub>3</sub>, and the reaction of O<sub>3</sub> with O at D region altitudes. The first calculations of O<sup>*</sup><sub>2</sub>( <i>j</i>) number densities, <i>N</i><sub><i>j</i></sub>, are obtained by solving continuity equations for the models of harmonic and anharmonic oscillator energy levels, <i>j</i>=1-22. It is found that day time values of <i>N</i><sub><i>j</i></sub> are less than nighttime values. We also show that the photoionization of O<sup>*</sup><sub>2</sub> ( <i>j</i> ≥ 11) by L<sub>α</sub>-radiation has no influence on the D region <i>N</i><sub><i>e</i></sub>. In the nighttime D region the photoionization O<sup>*</sup><sub>2</sub> ( <i>j</i> ≥ 11) by scattered <i>L</i><sub>α</sub>-radiation can be a new source of O<sup>+</sup><sub>2</sub>. We show that the N<sup>*</sup><sub>2</sub> and O<sup>*</sup><sub>2</sub> de-excitation effect on the electron temperature is small in the E region of the ionosphere and cannot explain experimentally observed higher electron temperatures.