Study of the Ground Level Enhancements effect on atmospheric electric properties and mineral dust particle charging

Abstract

The effect of Ground Level Enhancements (GLEs) on the atmospheric and dust particles electrical properties is studied. It has been found that in the case of fair weather conditions, GLE events enhance the atmospheric electrical conductivity, reduce the columnar resistance, and modify the fair weather electric field, air–earth conduction current, and possibly the Ionospheric Potential (IP) in a way that depends on the geomagnetic cut-off rigidity of the location and the altitude. If a dust particle layer is present, GLE events tend to cancel its electrical effects in the ambient atmosphere. This means that the enhancement of the electric field and the reduction of atmospheric electrical conductivity, caused by the ion attachment to dust particles, not only tend to return to their ambient fair weather values, but they can be further modified as if the dust layer was not present. Finally, in terms of dust particles’ electrical properties, GLE events tend to modify the ion attachment mechanism, and in principle, the particle net charge, and the electric field “sensed” by them, increase. Nevertheless, since the electrical force magnitude is up to six orders of magnitude less than gravity, the increase of the particles’ electrical properties is not sufficient to modify the particle settling dynamics and settling velocities.