Airglow and ionosphere
Résumé
The ionospheric glow is due to the desexcitation of neutral or ion molecules and atoms. Its computation requires the knowledge of a number of parameters including the production of the excited species. Several processes occur: resonant and fluorescent scattering, chemical reactions, recombination, photo-absorption or collisions. In the ionosphere, the collisions with the suprathermal electrons are the major process at work (ca depend des emissions!!) The modelling of the ionospheric airglow requires therefore the computation of the collision impact excitation and the computation of the suprathermal electron flux. This is made through the solving of the kinetic Boltzmann equation. However, in order to solve this equation we need to know some macroscopic parameters, namely the electron density and temperature. They are computed through the fluid Boltzmann equations. In this talk, we will first present our coupled kinetic - fluid model and show how the study of the Martian case implies to reconsider the classical equations. We will then show the results of the ions and excitation productions. We will focus on some specific excitation rates that create the Martian ionospheric airglow and show our results particularly on OI 135, 297, 558 and 630 nm,CO2+ 288 nm, 289.7 nm, Mg+ and Mg at 280 and 285 nm. We finally give some future extensions in the frame of the MEMO project.