Behaviour of harmonic components of the geomagnetic field during counter electrojet events
Abstract
Data on the horizontal component of the earth's magnetic field obtained during 60 days of counter electrojet events have been subjected to harmonic analysis for the stations of Trivandrum, Kodaikanal, Annamalainagar and Alibag. A similar analysis has been done for 60 quiet days also as control days with a view to find out the changes in the relative amplitudes and phases of the various harmonic components which contribute to the abnormal time variation of the geomagnetic field on counter electrojet days. It is found that the amplitudes of the semidiurnal and ter-diurnal components are greater on counter electrojet days compared to the quiet days, while a less marked trend of a decrease in the amplitude of the diurnal component is observed on the counter electrojet days are found always to lead those of the respective components on the control days. During strong counter electrojet events, the phase lead is as much as 2 to 4 hours. The implications of the analytical results are discussed in the light of present theories on counter electrojet.
- Publication:
-
Journal of Geomagnetism and Geoelectricity
- Pub Date:
- 1988
- DOI:
- 10.5636/jgg.40.111
- Bibcode:
- 1988JGG....40..111S
- Keywords:
-
- Electrojets;
- Geomagnetism;
- Harmonic Analysis;
- Diurnal Variations;
- Magnetic Variations