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  • Article
  • Open Access

Solar flare effects on the geomagnetic elements during normal and counter electrojet periods

  • 1, 2Email author,
  • 3,
  • 3,
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Earth, Planets and Space201451:BF03351565

  • Received: 4 March 1999
  • Accepted: 13 August 1999
  • Published:


The paper describes the study of solar flare effects (sfe) on horizontal (H), eastward (Y) and vertical (Z) components of the geomagnetic field at the Indo-USSR chain of magnetic observatories extending from the magnetic latitudes 0° to 45°N, a network not available any where else in the world. Events are selected when strong, normal and reversed (counter) equatorial electrojet are in existence as well as when only a partial counter electrojet is present.

During a strong and normal electrojet event time, sfe consists of a positive impulse in H at all stations, the amplitude of H following the latitudinal variation similar to that of the quiet day monthly mean, Sq (H). The sfe in Y is negative at all the stations. Sfe in Z shows positive impulse at the four-electrojet stations and negative at other stations. During a counter electrojet period the effect of solar flare on H field is negative impulse at electrojet stations, positive at low latitude and again negative at stations north of Sq focus. Sfe in Y is small at all the equatorial nd negative at higher latitude stations. However, sfe (Z) is negative at the equatorial latitudes.

During a partial counter electrojet period the observed effect is the combination of an increase of the planetary current component and the decrease of the electrojet component, giving rise to a negative impulse in H at equatorial stations and apositive impulse in H, increasing with increasing distance from the equator. These results are presented and discussed.


  • Latitudinal Variation
  • Equatorial Electrojet
  • Negative Impulse
  • Equatorial Latitude
  • Positive Impulse