Operational Inner Magnetosphere Transport and Acceleration Model (IMPTAM) for specification of radiation environment for surface charging

Surface charging, the process of charge deposition on covering insulating surfaces of satellites is directly linked to the space environment at a time scale of a few tens of seconds. Accurate specification of the space environment at different orbits is of a key importance. We present the operational model for low energy (< 200 keV) electrons in the inner magnetosphere, called Inner Magnetosphere Particle Transport and Acceleration model (IMPTAM). This model in its various versions has been operating online since March 2013 (imptam.fmi.fi and imptam.engin.umich.edu) and it is driven by the real time solar wind (solar wind number density, dynamic pressure and velocity) and Interplanetary Magnetic Field (Y and Z components and total magnitude) parameters and by the real time Dst and Kp indices. The model provides the low energy electron (and proton) flux at all L-shells and at all satellite orbits, when necessary. We present several products, such as (1) 3D distributions of 1-200 keV electron fluxes (dependent on L, MLT, pitch angle and energy) inside 10 Re, (2) electron fluxes along any given satellite orbit for any given energy, (3) electron spectra at any location inside 10 Re as input to software computing potentials at satellite surfaces.