Reflected and diffuse ions backstreaming from the earth's bow shock 1. Basic properties

Journal Article · Mon Jun 01 04:00:00 EDT 1981 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA086iA06p04397· OSTI ID:6214932

Bonifazi, C; Moreno, G

Plasma data supplied by the ISEE 2 solar wind experiment are used to perform the first extended statistical analysis of the basic moments of the ions backstream from the earth's bow shock. The analysis is based on 3253 ion spectra, corresponding to a total observation time of approx. =87 hours. It turns out that the density and total energy density of the backstream ions are, on the average, equal to approx. =1% and approx. =10% of those of the solar wind, respectively. The distinction between the 'reflected' and 'diffuse' populations has been confirmed and put on a quantitive basis using the ratio A = V /sub B/P/w/sub B/P between the bulk velocity and the rms thermal speed of the ions. The reflected ions are characterized by a bulk velocity V/sub B/P of the order of 2 times the solar wind velocity and by a temperature of approx.7 x 10/sup 6/ K. In contrast, the diffuse ions have, on the average, a bulk velocity 1.2 times the solar wind velocity and a temperature of 40 x 10/sup 6/ K. Therefore the total energy density of the diffuse ions is approx. =30% larger than that of the reflected ions. Finally, the kinetic and thermal energy densities are distributed quite differently in the two ion populations: in fact, approx. =70% of the total energy density is kinetic for the reflected ions, while this percentage decreases to approx. =20% for the diffuse ions.

• Research Organization: Instituto Plasma Spazio, Consiglio Nazionale delle Ricerche, Frascati, Italy
• OSTI ID: 6214932
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 86:A6; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKSCATTERING
CHARGED PARTICLES
EARTH ATMOSPHERE
ENERGY
ENERGY DENSITY
ENERGY SPECTRA
ION DENSITY
ION TEMPERATURE
IONS
KINETIC ENERGY
MAGNETOSPHERE
REFLECTION
SCATTERING
SOLAR ACTIVITY
SOLAR WIND
SPECTRA