STRUCTURE OF THE LOW-LATITUDE MAGNETOPAUSE - MAGION-4 OBSERVATIONS

The aims of this paper are (1) briefly to describe the plasma devices onboard the MAGION-4 satellite, launched on 3 August 1995, of the INTE RBALL project: and (2) to discuss first observations made near the mag netopause region. During the presented boundary crossings the MAGION-4 observed quasiperiodic pulses of magnetosheath-like plasma in a regio n of low plasma density. This region is located just earthwards of the magnetopause and is populated by a plasma which, except for the densi ty, has the same parameters as in the magnetosheath. Deeper in the mag netosphere, the encounter of a layer of hot electrons and high-energy ions was interpreted as low-latitude boundary layer.