Journal cover Journal topic
Annales Geophysicae An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 1.490 IF 1.490
  • IF 5-year value: 1.445 IF 5-year
    1.445
  • CiteScore value: 2.9 CiteScore
    2.9
  • SNIP value: 0.789 SNIP 0.789
  • IPP value: 1.48 IPP 1.48
  • SJR value: 0.74 SJR 0.74
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 88 Scimago H
    index 88
  • h5-index value: 21 h5-index 21
Volume 24, issue 10
Ann. Geophys., 24, 2667–2684, 2006
https://doi.org/10.5194/angeo-24-2667-2006
© Author(s) 2006. This work is distributed under
the Creative Commons Attribution 3.0 License.
Ann. Geophys., 24, 2667–2684, 2006
https://doi.org/10.5194/angeo-24-2667-2006
© Author(s) 2006. This work is distributed under
the Creative Commons Attribution 3.0 License.

  20 Oct 2006

20 Oct 2006

Longitudinal drift of substorm electrons as the reason of impulsive precipitation events and VLF emissions

A. A. Lubchich1, A. G. Yahnin1, E. E. Titova1, A. G. Demekhov2, V. Yu. Trakhtengerts2, J. Manninen3, and T. Turunen3 A. A. Lubchich et al.
  • 1Polar Geophysical Institute, Apatity, Russia
  • 2Institute of Applied Physics, Nizhny Novgorod, Russia
  • 3Geophysical Observatory, FIN-99600 Sodankylä, Finland

Abstract. Using the data from satellite CRRES and three geostationary LANL spacecraft, the propagation of an electron cloud from midnight to the evening sector is investigated. An electron cloud was injected during a weak isolated substorm that developed on a quiet geomagnetic background. It is found that within the local time sector from 03:00 until at least 08:00 MLT, the propagation of electrons at perpendicular pitch-angles is well described by a simple model of drift in the dipole magnetic field. The flux levels in the field-aligned electrons increase simultaneously with the flux at perpendicular pitch angles, which is attributed to the pitch angle diffusion by the whistler mode. This pitch-angle diffusion leads to precipitation of electrons from a drifting cloud and an increase in the ionospheric electron density, simultaneously observed above Tromsø, Norway, by the EISCAT UHF radar in the morning sector (04:40–05:25 MLT). The precipitation develops as quasi-periodic pulses with a period of about 100 s. We discuss the models of pulsating precipitation due to the whistler cyclotron instability and show that our observations can be explained by such a model.

Publications Copernicus
Download
Citation