Articles | Volume 18, issue 9
Ann. Geophys., 18, 1067–1072, 2000

Special issue: IXe EISCAT

Ann. Geophys., 18, 1067–1072, 2000

  30 Sep 2000

30 Sep 2000

Combined ESR and EISCAT observations of the dayside polar cap and auroral oval during the May 15, 1997 storm

H. Liu2,1, K. Schlegel1, and S.-Y. Ma3,2 H. Liu et al.
  • 1Max-Planck-Institut für Aeronomie, Max-Planck-Str. 2, D-37191 Katlenburg-Lindau, Germany
  • e-mail:
  • 2Space physics department, Wuhan University, Wuhan 430072, China
  • 3Wuhan Ionospheric Observatory, Wuhan Institute of Physics and Mathematics, Chinese Academy of Science, Wuhan 430071, China
  • Correspondence to: Huixin Liu

Abstract. The high-latitude ionospheric response to a major magnetic storm on May 15, 1997 is studied and different responses in the polar cap and the auroral oval are highlighted. Depletion of the F2 region electron density occurred in both the polar cap and the auroral zone, but due to different physical processes. The increased recombination rate of O+ ions caused by a strong electric field played a crucial role in the auroral zone. The transport effect, however, especially the strong upward ion flow was also of great importance in the dayside polar cap. During the main phase and the beginning of the recovery phase soft particle precipitation in the polar cap showed a clear relation to the dynamic pressure of the solar wind, with a maximum cross-correlation coefficient of 0.63 at a time lag of 5 min.

Key words: Ionosphere (auroral ionosphere; polar ionosphere) - Magnetospheric physics (storms and substorms)

Special issue