The Plasmapause Formation (original) (raw)

Introduction The plasmasphere is a characteristic region of the magnetosphere whose outer surface the plasmapause (PP) was discovered in 1963 by D. L. Carpenter. Fig. 1 illustrates the shape of the plasmasphere encircling the Earth and extending in the equatorial plane from the topside ionosphere up to 3 Earth radii or more. The thin region immediately outside the PP has lately been called Plasmapause Boundary Layer (PBL). The shape and extend of these regions depend strongly on the level of geomagnetic activity (Kp-index), on magnetic local time (MLT) and universal time (UT). The plasmasphere is filled with thermal electrons, protons, and other ions of ionospheric origin whose energies are less than 1-2 eV. They spiral along the geomagnetic field lines, and revolve around the Earth almost with the angular velocity of the Earth. These charged particles are trapped within the gravitational field and the magnetospheric electric fields.