Letter to the Editor: Geomagnetic storm effects at low latitudes

R. G. Rastogi (1, 2)

1 Swinburne University of Technology (Hawthorn campus)
2 Department of Physics [Ahmedabad]

The geomagnetic horizontal (H) field from the chain of nine observatories in India are used to study the storm-time and disturbance daily variations. The peak decrease in storm-time variation in H showed significant enhancements at the equatorial electrojet stations over and above the normally expected decrease due to the ring current effects corrected for geomagnetic latitudes. The disturbance daily variation of H at equatorial stations showed a large decrease around midday hours over and above the usual dawn-maximum and dusk-minimum seen at any mid-latitude stations around the world. These slow and persistent additional decreases of H of disturbance daily variation at equatorial latitudes could be the effect of a westward electric field due to the Disturbance Ionospheric dynamo coupled with abnormally large electrical conductivities in the E region over the equator.

Domaines: Océan, Atmosphère; Sciences de la Terre

R. G. Rastogi. Letter to the Editor: Geomagnetic storm effects at low latitudes. Annales Geophysicae, 1999, 17 (3), pp.438-441. ⟨hal-00316562⟩