Electromagnetic effects in the Earth's ionosphere and magnetosphere caused by a cosmic body

Abstract

The purpose of the present investigation is to study possible electromagnetic effects in the Earth's ionosphere and magnetosphere, which are caused by a cosmic body impact onto the atmosphere and by a cosmic body passage through the magnetosphere. An analysis of a cosmic body impact onto the atmosphere is carried out for a meteoroid with the kinetic energy of the order of 1 kt TNT. Such meteoroids are usually detected in the Earth's atmosphere several times a year. Variation of the electron density in the ionospheric plasma and excitation of plasma turbulence as a result of meteoroid impact events are shown to be associated with an appearance of the acoustic perturbation formed in the atmosphere due to the impact of the meteoroid. The evolution of the acoustic perturbation is studied. The electron density variation and parameters of ion-acoustic waves (and, in particular, ion-acoustic solitons), which are associated with the acoustic perturbation, are estimated. Variations of geomagnetic field strength caused by the meteoroid impact events and the rates of electron acceleration as a result of the interaction of the cosmic body with the Earth's atmosphere are evaluated. Most significant electromagnetic effects in the Earth's magnetosphere can be caused by a cosmic body embedded in a dust cloud. It is demonstrated that for an adequate description of the dust cloud with the magnetosphere the process of dust particle charging during the meteoroid passage should be taken into account. The presence of charged dust particles can result in the formation of a current system and (for sufficiently large density of dust particles, e.g. close to that related to the comet Shoemaker-Levy 9) in violation of the magnetic structure of the magnetosphere in the vicinity of the dust cloud. The possibility of auroral processes before the effective interaction of the cosmic body with the atmosphere, which are triggered by fast particles created due to Fermi acceleration process, is demonstrated.