The latitude and radial dependence of shock acceleration in the heliosphere

Journal Article · Mon Feb 01 04:00:00 EST 1988 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA093iA02p00991· OSTI ID:6096450

Gold, R E; Decker, R B; Krimigis, S M ^[1]; Lanzerotti, L J; Maclennan, C G ^[2]

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1. Johns Hopkins Univ., Laurel, MD (United States)
2. AT and T Bell Labs., Murray Hill, NJ (United States)

Voyagers 1 and 2 have observed interplanetary shock acceleration of {approx lt}2 MeV ions at radial distances of > 25 AU and heliographic latitudes of up to {approximately}30{degrees}. The previously reported negative latitude gradient in the intensities of accelerated ions at these energies persists over the entire range of latitudes and radial distances measured. The energy spectra of the shock acceleration events at Voyagers 1 and 2 are similar. A dramatic decrease in the flux of {approx lt}2 MeV ions in the outer heliosphere was observed by both Voyager spacecraft in 1985. The decrease was observed at {approximately}30{degrees} as well as in the solar equatorial plane. At the time of the decrease, Voyager 1 was at {approximately}22 and {approximately}6 AU further from the sun than Voyager 2. However, the decrease began within an {approximately}12 day interval at both spacecraft. Comparisons with data from the IMP 8 spacecraft near Earth show that the decrease propagated outward from the Sun at {approximately}570 km/s. The timing of the large decrease between the two Voyager spacecraft implies a latitude gradient in the velocity of interplanetary shocks of {approximately}4.2 km/s per degree of latitude above the solar equator.

• OSTI ID: 6096450
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 93:A2; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

660000* -- Physics-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ATMOSPHERES
CHARGED PARTICLES
COMPARATIVE EVALUATIONS
ENERGY SPECTRA
EVALUATION
HELIOSPHERE
IMP SATELLITES
INTERPLANETARY SPACE
IONS
SATELLITES
SHOCK WAVES
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR WIND
SPACE
SPACE VEHICLES
SPECTRA
VEHICLES
VOYAGER SPACE PROBES