Magnetopause boundary structure deduced from the high-time resolution particle experiment on the Equator-S spacecraft
Abstract
An electrostatic analyser (ESA) onboard the Equator-S spacecraft operating in coordination with a potential control device (PCD) has obtained the first accurate electron energy spectrum with energies approx7 eV-100 eV in the vicinity of the magnetopause. On 8 January, 1998, a solar wind pressure increase pushed the magnetopause inward, leaving the Equator-S spacecraft in the magnetosheath. On the return into the magnetosphere approximately 80 min later, the magnetopause was observed by the ESA and the solid state telescopes (the SSTs detected electrons and ions with energies approx20-300 keV). The high time resolution (3 s) data from ESA and SST show the boundary region contains of multiple plasma sources that appear to evolve in space and time. We show that electrons with energies approx7 eV-100 eV permeate the outer regions of the magnetosphere, from the magnetopause to approx6Re. Pitch-angle distributions of approx20-300 keV electrons show the electrons travel in both directions along the magnetic field with a peak at 90176 indicating a trapped configuration. The IMF during this interval was dominated by Bx and By components with a small Bz.
- Publication:
-
Annales Geophysicae
- Pub Date:
- December 1999
- DOI:
- 10.1007/s00585-999-1574-3
- Bibcode:
- 1999AnGeo..17.1574P