Articles | Volume 25, issue 3
Ann. Geophys., 25, 661–673, 2007
https://doi.org/10.5194/angeo-25-661-2007
Ann. Geophys., 25, 661–673, 2007
https://doi.org/10.5194/angeo-25-661-2007

  29 Mar 2007

29 Mar 2007

TRANS4: a new coupled electron/proton transport code – comparison to observations above Svalbard using ESR, DMSP and optical measurements

C. Simon1, J. Lilensten1, J. Moen2,3, J. M. Holmes3, Y. Ogawa4, K. Oksavik5, and W. F. Denig6,* C. Simon et al.
  • 1Laboratoire de Planétologie de Grenoble, Grenoble, France
  • 2Plasma and Space Physics Group, Department of Physics, University of Oslo, Norway
  • 3Department of Arctic Geophysics, University Centre in Svalbard (UNIS), Longyearbyen, Norway
  • 4Solar-Terrestrial Environment Laboratory, Nagoya University, Japan
  • 5The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
  • 6Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, MA, USA
  • *now at: National Geophysical Data Center, NOAA, Boulder, CO, USA

Abstract. We present for the first time a numerical kinetic/fluid code for the ionosphere coupling proton and electron effects. It solves the fluid transport equations up to the eighth moment, and the kinetic equations for suprathermal particles. Its new feature is that for the latter, both electrons and protons are taken into account, while the preceding codes (TRANSCAR) only considered electrons. Thus it is now possible to compute in a single run the electron and ion densities due to proton precipitation. This code is successfully applied to a multi-instrumental data set recorded on 22 January 2004. We make use of measurements from the following set of instruments: the Defence Meteorological Satellite Program (DMSP) F-13 measures the precipitating particle fluxes, the EISCAT Svalbard Radar (ESR) measures the ionospheric parameters, the thermospheric oxygen lines are measured by an all-sky camera and the Hα line is given by an Ebert-Fastie spectrometer located at Ny-Ålesund. We show that the code computes the Hα spectral line profile with an excellent agreement with observations, providing some complementary information on the physical state of the atmosphere. We also show the relative effects of protons and electrons as to the electron densities. Computed electron densities are finally compared to the direct ESR measurements.

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