Night-time enhancements of ionospheric electron content at L = 4 during substorms

Journal Article · Wed Jul 01 04:00:00 EDT 1981 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL008i007p00815· OSTI ID:5526301

Hargreaves, J K; Hunsucker, R D

Observations of the ATS-6 radio beacon from Fairbanks show structured enhancements of the night-time electron content during substorms. The probability of their occurence increases with the level of magnetic disturbance, and they are most likely to be observed when the daily sum of K indices exceeds 20 in winter or 30 in summer. There is a remarkably close coincidence between these electron-constant enhancements and auroral absorption events detected by a riometer, though the relative magnitudes vary with the time of day. Electron density profiles measured with the Chatanika incoherent-scatter radar confirm that the electron density at 90 km is enhanced during auroral absorption events. However, D and E-region ionization is insufficient to account for the observed enhancement of the electron content, and an F-region effect is a more likely cause. During one such event the F-region critical frequency was 8 MHz.

• Research Organization: Department of Environmental Sciences, University of Lancaster, Lancaster LA1 4YQ, England
• OSTI ID: 5526301
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 8:7; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED-PARTICLE PRECIPITATION
DAILY VARIATIONS
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ELECTRON DENSITY
FARADAY EFFECT
INCOHERENT SCATTERING
IONOSPHERE
MAGNETIC BAYS
MAGNETOSPHERE
PLANETARY IONOSPHERES
RADIATIONS
RADIOWAVE RADIATION
SCATTERING
VARIATIONS