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Last Updated: 05/26/2022

IMPTAM

Version: 1.1e-

The IMPTAM, version for electrons (Ganushkina et al., 2013, 2014, 2015, 2019), originally developed for ions (Ganushkina et al., 2001, 2005, 2006), traces distributions of electrons in the drift approximation (first and second adiabatic invariants conserved) with arbitrary pitch angles from the plasma sheet (starting at 10 RE) to the inner L shell regions (2-3 RE) with energies reaching up to hundreds of keVs in time-dependent magnetic and electric fields. Liouville's theorem is used to gain information on the entire distribution function with losses taken into account. For electron losses, convection outflow and pitch angle diffusion are considered. Instead of using the pitch angle diffusion coefficients directly, the parameterizations of the electron lifetimes due to interactions with chorus and hiss waves obtained by Orlova and Shprits [2014] and Orlova et al. [2014, 2016] with plasmapause location by Carpenter and Anderson [1992] are incorporated. For the obtained distribution function, radial diffusion is applied by solving the radial diffusion equation (Schulz & Lanzerotti, 1974). Kp-dependent radial diffusion coefficients DLL for the magnetic field fluctuations are computed following Brautigam and Albert (2000). After that, the order of calculation is repeated: First, solve transport with losses and then apply the diffusion. Inside IMPTAM, the set of models is (1) a dipole model for the internal magnetic field, (2) T96 model Tsyganenko (1995) for the external magnetic field, and (3) Boyle et al. (1997) polar cap potential mapped to the magnetosphere. We set the model boundary at 10 RE and use the kappa electron distribution function. Parameters of the kappa distribution function are the number density n and temperature T in the plasma sheet given by the empirical model derived from THEMIS data by Dubyagin et al. (2016).

Caveats:

Requires conservation of first and second adiabatic invariants.

Details can be found here http://citrine.engin.umich.edu/imptam/

Inputs

IMF and solar wind parameters, geomagnetic indices (Kp, Dst, AL)

Outputs

Electron fluxes in the energy range from 1 to 300 keV everywhere in 3D inner magnetosphere at distances from 2 to 10 RE, with specific output at GEO, GTO and MEO orbits.

Model is time-dependant.

Domains

  • Magnetosphere / Global Magnetosphere
  • Magnetosphere / Inner Magnetosphere / RingCurrent

Space Weather Impacts

  • Near-earth radiation and plasma environment (aerospace assets functionality)

Phenomena

  • Geomagnetic Storms
  • Geomagnetic Sub-storms
  • Plasma Sheet
  • Particle Dynamics
  • Inner Magnetosphere and Outer Magnetosphere / Tail Coupling

Publications

Code

Code Languages: C++ and FORTRAN, Python

Contacts

Publication Policy

In addition to any model-specific policy, please refer to the General Publication Policy.