Multispacecraft observations of energetic ions upstream and downstream of the bow shock

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL016i006p00571· OSTI ID:6017607

Scholer, M; Mobius, E; Kistler, L M; Klecker, B; Ipavich, F M

We present simultaneous measurements of energetic protons and alpha particles inside and outside of the magnetopause, immediately upstream, and downstream as well as further upstream of the bow shock. A comparison between the intensity at the bow shock and further upstream results in an e-folding distance at 30 keV of /similar to/6.2 R/sub E/. After transformation of the angular distribution into the solar wind frame a diffusion coefficeint of kappa/sub /parallel///similar to/3 R/sub E/ is obtained from the anisotropy and the intensity gradient. Immediately downstream of the bow shock the anisotropy in the shock frame is directed toward the magnetopause. After transformation into the plasma rest frame the distribution is isotropic. The intensity in the magnetosheath just outside the magnetopause is smaller than the intensity behind the bow shock. Thus, in the magnetosheath there is no gradient or streaming in the upstream direction. The spectra, intensities, and relative abundances in the magnetosheath and inside the magnetosphere are totally different. These observations are consistent with first order Fermi acceleration at the bow shock and subsequent downstream convection, and exclude a magnetospheric source for these particles. /copyright/ American Geophysical Union 1989

• Research Organization: Institut fur extraterrestrische Physik, Max-Planck-Institut fur Physik und Astrophysik, Garching, FRG(DE); Department of Physics and Astronomy, University of Maryland, College Park
• OSTI ID: 6017607
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 16:6; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ALPHA SPECTRA
ANGULAR DISTRIBUTION
ANISOTROPY
CONVECTION
DATA ANALYSIS
DISTRIBUTION
ENERGY SPECTRA
ENERGY TRANSFER
EXPLORER SATELLITES
HEAT TRANSFER
MAGNETOPAUSE
MASS TRANSFER
PLASMA ACCELERATION
PROTON SPECTRA
SATELLITES
SOLAR ACTIVITY
SOLAR WIND
SPECTRA