Energetic ion composition in the subsolar magnetopause and boundary layer
Abstract
Energetic ion mass spectrometer data obtained on ISEE 1 have shown that the plasma in the subsolar magnetospheric boundary layer, magnetopause, and adjacent magnetosheath have an ionospheric component (He+ and O+) in addition to the solar wind component (H+ and He++). We have examined in detail nine intervals where the location of the subsolar magnetopause and boundary layer are well defined by the ISEE 1 fast plasma and magnetic field measurements. In five of the identified boundary layer intervals, keV He+ ions were observed; energetic O+ ions were seen, above background, in two of the boundary layers where He+ was observed. The temporal resolution of the ion mass spectrometer was too coarse to rule out the possibility of He+ or O+ ions being present in the four remaining intervals. Ionospheric He+ ions were also observed in the magnetosheath in two (and O+ in one) of the nine intervals studied.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- April 1982
- DOI:
- 10.1029/JA087iA04p02139
- Bibcode:
- 1982JGR....87.2139P
- Keywords:
-
- Boundary Layer Plasmas;
- Energetic Particles;
- Magnetopause;
- Mass Spectroscopy;
- Positive Ions;
- Space Plasmas;
- Helium Ions;
- International Sun Earth Explorer 1;
- Magnetosheath;
- Magnetospheric Ion Density;
- Oxygen Ions