AISstorm 2.1 - Modeling Particle induced atmospheric Ionization

Kurzfassung

AISstorm (Atmospheric Ionization during Substorms Model) derives the global atmospheric ionization due to particle precipitation based on in-situ particle measurements. The model covers auroral precipitation as well as solar particle events on an altitude range of about 250km down to 16km for protons and down to 70km for electrons. The ionization of alpha particles is also included, but in a smaller height range. The overall structure is divided into an empirical model, which determines the flux of the 2D precipitation particles, and a numerical model, which determines the ionization profile of the individual particles. The combination of these two models results in a high-resolution 3D particle ionization rate pattern. The AISstorm is the successor to the Atmospheric Ionization Module Osnabrück (AIMOS). The main advantage of the updated ionization rates is a higher dynamic during substorms and during the onset of geomagnetic storms, especially in the mesosphere - in agreement with observations. The internal structure of the model has been completely revised in AISstorm. The main aspects are: a) an internal magnetic coordinate system, b) the inclusion of sub-storm properties, c) a higher temporal resolution, d) a higher spatial resolution, e) an energy-specific, separate treatment of auroral precipitation, polar cap precipitation and crosstalk-affected areas, f) a better MLT resolution. The paper compares the new ionization rates with AIMOS 1.6, AISstorm 2.0 and the HEPPA III multi-model study.