Articles | Volume 30, issue 10
Ann. Geophys., 30, 1495–1501, 2012

Special issue: Structure, composition, and dynamics of the middle atmosphere...

Ann. Geophys., 30, 1495–1501, 2012

Regular paper 05 Oct 2012

Regular paper | 05 Oct 2012

Electron loss and meteoric dust in the mesosphere

M. Friedrich1, M. Rapp2,*, T. Blix3,4, U.-P. Hoppe4,**, K. Torkar5, S. Robertson6, S. Dickson6, and K. Lynch7 M. Friedrich et al.
  • 1Graz University of Technology, Graz, Austria
  • 2Leibniz Institute of Atmospheric Physics, Kühlungsborn, Germany
  • 3Norwegian Defence Research Establishment, Kjeller, Norway
  • 4University of Oslo, Norway
  • 5Space Research Institute, Austrian Academy of Sciences, Graz, Austria
  • 6Department of Physics, University of Colorado, Boulder, USA
  • 7Department of Physics and Astronomy, Hanover, NH 03755, USA
  • *now at: German Aerospace Center, Institute of Atmospheric Physics, Oberpfaffenhofen, Germany
  • **on leave from: Norwegian Defence Research Establishment, Kjeller, Norway

Abstract. The ionosphere is always assumed to contain equal numbers of positive and negative charges in a given volume (quasineutrality). Hence fewer electrons than positive charges are an indication of negative charges other than electrons. Theories predict and in-situ mass spectrometer measurements confirmed that these negative charges are negative ions, but recent experimental results suggest that other scavengers of free electrons can also be active in the mesosphere. Outside the polar summer mesosphere this additional removal of electrons is today believed to be due to meteoric dust, which maximises in the mesosphere. Data predominantly from the recent ECOMA flights are used to test this presumption. Six sounding rockets carried different dust detectors, as well as probes for electrons and ions. With such an instrumental ensemble one can assess whether indeed the existence of meteoric dust removes more electrons than would be expected from gas phase ion chemistry alone. Other factors potentially impacting on electron removal are also discussed in the paper.