Precursor to equatorial spread-F in OI 630.0 nm dayglow
Abstract
A unique OI 630.0 nm dayglow photometer operated from Waltair (10.0° N dip lat.), a-low-latitude station in India, in a bidirectional mode, i.e., over zenith and at 20° elevation pointing north, has revealed features associated with the evolution of the Equatorial Ionization Anomaly (EIA) The estimated strength of the EIA on a particular day based on these features reveal that significant differences exist in the EIA contribution to OI 630.0 nm on equatorial spread-F (ESF) and non-ESF days. There exists a precursor in the OI 630.0 nm dayglow which enables the prediction of ESF at least 3 hours prior to its actual occurrence and hence points to the significant control of daytime EIA-related processes in the triggering of the post-sunset ESF.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- December 1994
- DOI:
- 10.1029/94GL02732
- Bibcode:
- 1994GeoRL..21.2797S
- Keywords:
-
- Anomalies;
- Atmospheric Ionization;
- Dayglow;
- Earth Ionosphere;
- Equatorial Atmosphere;
- Ionosondes;
- Spectral Emission;
- Spread F;
- All Sky Photography;
- Cameras;
- Diurnal Variations;
- Periodic Variations;
- Photometers;
- Radar Measurement;
- Ionosphere: Equatorial ionosphere;
- Ionosphere: Ionosphere-atmosphere interactions;
- Ionosphere: Ionospheric irregularities;
- Atmospheric Composition and Structure: Airglow and aurora