Articles | Volume 23, issue 1
Ann. Geophys., 23, 135–145, 2005
https://doi.org/10.5194/angeo-23-135-2005

Special issue: Eleventh International EISCAT Workshop

Ann. Geophys., 23, 135–145, 2005
https://doi.org/10.5194/angeo-23-135-2005

  31 Jan 2005

31 Jan 2005

Comparison of the characteristic energy of precipitating electrons derived from ground-based and DMSP satellite data

M. Ashrafi, M. J. Kosch, and F. Honary M. Ashrafi et al.
  • Department of Communications Systems, Lancaster University, Lancaster, LA1 4WA, UK

Abstract. Energy maps are important for ionosphere-magnetosphere coupling studies, because quantitative determination of field-aligned currents requires knowledge of the conductances and their spatial gradients. By combining imaging riometer absorption and all-sky auroral optical data it is possible to produce high temporal and spatial resolution maps of the Maxwellian characteristic energy of precipitating electrons within a 240240 common field of view. These data have been calibrated by inverting EISCAT electron density profiles into equivalent energy spectra. In this paper energy maps produced by ground-based instruments (optical and riometer) are compared with DMSP satellite data during geomagnetic conjunctions. For the period 1995-2002, twelve satellite passes over the ground-based instruments' field of view for the cloud-free conditions have been considered. Four of the satellite conjunctions occurred during moderate geomagnetic, steady-state conditions and without any ion precipitation. In these cases with Maxwellian satellite spectra, there is 71% agreement between the characteristic energies derived from the satellite and the ground-based energy map method.