Articles | Volume 18, issue 9
Ann. Geophys., 18, 1210–1215, 2000

Special issue: IXe EISCAT

Ann. Geophys., 18, 1210–1215, 2000

  30 Sep 2000

30 Sep 2000

First EISCAT measurement of electron-gas temperature in the artificially heated D-region ionosphere

A. Kero1, T. Bösinger1, P. Pollari1, E. Turunen2, and M. Rietveld3 A. Kero et al.
  • 1University of Oulu, Department of Physical Sciences, FIN-90401 Oulu, Finland
  • 2Geophysical Observatory, FIN-9960 Sodankylä, Finland
  • 3EISCAT, 9027 Ramfjordbotn, Norway; also at Max-Planck-Institut für Aeronomie, D-37191 Katlenburg-Lindau, Germany

Abstract. The ionospheric electron gas can be heated artificially by a powerful radio wave. According to our modeling, the maximum effect of this heating occurs in the D-region where the electron temperature can increase by a factor of ten. Ionospheric plasma parameters such as Ne, Te and Ti are measured by EISCAT incoherent scatter radar on a routine basis. However, in the D-region the incoherent scatter echo is very weak because of the low electron density. Moreover, the incoherent scatter spectrum from the D-region is of Lorentzian shape which gives less information than the spectrum from the E- and F-regions. These make EISCAT measurements in the D-region difficult. A combined EISCAT VHF-radar and heating experiment was carried out in November 1998 with the aim to measure the electron temperature increase due to heating. In the experiment the heater was switched on/off at 5 minute intervals and the integration time of the radar was chosen synchronously with the heating cycle. A systematic difference in the measured autocorrelation functions was found between heated and unheated periods.

Key words: Ionosphere (active experiments; plasma temperature and density; wave propagation)

Special issue