Energetic particle population in the high-latitude geomagnetosphere

Abstract

In accordance with model concept and quantitative estimates (Shabansky, 1972; Shabansky and Antonova, 1968; Antonova and Shabansky, 1976) energetic particles distribution and dynamics in high-latitude dayside geomagnetosphere are determined by nondipolar magnetic field behaviour, especially by off equatorial field strength minima, existing both on closed and on open field lines, and are greatly affected by the proximity. Energetic particles enhancement in the high-latitude traps was observed on PROGNOZ 3 and 7 S/C. Additional confirmation have been obtained during the PROGNOZ 9 $,/C passes through dayside polar cusps and adjacent region at high altitude both in northern and southern hemispheres (Antonova, 1991,1996). Energetic particle fluxes in high latitude dayside magnetosphere are greatly increased during active periods. Recent observation of confined energetic heavy ion population in the polar cap onboard POLAR S/C (Chen et al., 1997, 1998) supports the model. Cross-drift-shell diffusion of particles accelerated during magnetospheric activity on nightside, is a plausible origin mechanism for the dayside high-latitude fluxes.