Towards a precise modelling of transport processes in planetary ionospheres: photoelectrons, magnetospheric electrons and protons
Résumé
Numerical simulations of planetary ionospheres (Earth, Mars, Venus and Titan) using Boltzmann's kinetic formalism have proved their efficiency in interpreting multi-instrumental data sets. We present now the last evolution of the Trans-* codes family, called Trans4, which takes simultaneously into account photoionisation and electron/proton precipitation effects. The kinetic transport is coupled to a fluid model, which yields electron and ion densities, temperatures, velocities and heating fluxes, directly comparable to incoherent scatter radar measurements. We describe the physics of the model in detail, from chemical inputs to collisions and magnetic mirroring. As an example, a multi-instrumental (ground-based and satellite) data set at high latitudes on Earth is studied, which shows the applicability and the interest of such a code while dealing with complex solar-planetary events. Perspectives on the other planets (Mars, Venus, Titan) are discussed, as well as future extensions (cosmic rays, radiative transfer, polarisation).