[Previous] | [Session 19] | [Next]
F. Leblanc (Service d'Aeronomie du CNRS, FRANCE), J.G. Luhmann (Space Science Laboratory, Berkeley, USA), R.E. Johnson (University of Virginia, USA), E. Chassefiere (Service d'Aeronomie du CNRS, FRANCE)
The effect of a Gradual Proton Event on Mars' atmosphere is described. The incident Solar Energetic Particles flux crosses the planetopause/magnetopause and bow shock derived from the interaction between Mars and the solar wind. The low energy particles at the exobase sputter the atmosphere generating a small loss of atmosphere but different in comparison with the other losses due to the pick-up ions and to the dissociative recombination of O2+ in the Martian atmosphere. The low energy particles also generate a significant heating of the atmosphere around the homopause in relation with the crustal magnetic field. The high energy particles cross the whole atmosphere, reach the surface and are a potential danger for any human exploration. We will describe in details these different effects with 3D models. We will also compare these effects with the ones due to the normal solar wind and to O+ pick-up ions. A sum-up of all the different loss mechanisms for present epoch will be made taking into account all the populations of incident particles into Mars' atmosphere, of the dissociative recombination mechanisms below the exobase and of the photoionization above it.