Structure and properties of the Earth plasmasphere. Experimental data and problems of their interpretation

Results of direct measurements of plasma concentration and temperature, as well as, mass and charged composition of plasmasphere ions are discussed. Data obtained during last ten years are mainly used. These data are shown to prove the excistence of two zones within plasmasphere, that is, the inner one (L<3) - stable, quasistationary and cold (Ti1 eV), essentially nonstationary with parameter high longitudinal gradients. The boundary of the outer zone, that is, plasmapause, manifests itself clearly in night-midnight time and in day time is usually blurred, it has complicated nonstationary structure, essentially changes depending on geomagnetic conditions and has asymmetry by local time, whereupon night and midday protrusicus of plasmapause stand out surely in the equatorial plane