Magnetospheric Effects on the Cosmic Dust Input into the Earth’s Atmosphere

Abstract

We investigate the role of the electromagnetic fields on the dynamics and distribution of sub-micron-sized cosmic dust grains entering the Earth’s magnetosphere. In addition to gravitational force and solar radiation pressure we have taken into account the electromagnetic forces acting on charged dust particles. The charging is a consequence of the fact that these grains are immersed in the plasma and radiative environment of the Earth. Numerical simulations were performed for three distinct populations of cosmic dust particles: cometary, lunar, and interplanetary origin. We show that the magnetosphere has a shielding property with an efficiency that depends on the size and the velocity of the incoming dust grains. These magnetospheric effects decrease the flux of interplanetary and lunar dust particles smaller than ring ≤ 0.1 (μm; however, the shielding is much less efficient for dust grains of cometary ori- gin due to their high approach velocity.