Evidence for a latitudinal gradient of the cosmic ray intensity associated with a change in the tilt of the heliospheric current sheet

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL013i008p00777· OSTI ID:5111469

Christon, S P; Stone, E C; Hoeksema, J Y

Since mid-1985, the average flux of >70 MeV/nucleon cosmic rays at Voyager 2 (r/sub 2/--17 AU, THETA/sub 2/--O/sup 0/) has been --3-5% greater than that at Voyager 1 (r/sub 1/--24 AU, THETA/sub 1/--26/sup 0/ N). This is the first direct observation over such a large radial range in which the galactic cosmic ray flux closer to the sun is higher than the flux farther from the sun for an extended period of time. This observation is consistent with the presence of a negative latitudinal gradient G/sub THETA/ = -0.36 +- 0.05 (or -0.60 +- 0.08 )%/deg, assuming a coexistent radial gradient G/sub r/ of 1 (or 2) %AU. We suggest that the appearance of this persistent negative latitudinal gradient may be due to the abrupt, large decrease of the heliospheric current sheet tilt to --20/sup 0/ in early 1985.

• Research Organization: California Institute of Technology, Pasadena, CA 91125
• OSTI ID: 5111469
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 13:8; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
COSMIC RADIATION
COSMIC RAY FLUX
CURRENTS
ELEMENTARY PARTICLES
FERMIONS
GEOGRAPHICAL VARIATIONS
HADRONS
IONIZING RADIATIONS
LATITUDE EFFECT
NUCLEONS
RADIATION FLUX
RADIATIONS
SOLAR RADIATION
SPACE DEPENDENCE
SPACE VEHICLES
STELLAR RADIATION
VARIATIONS
VEHICLES
VOYAGER SPACE PROBES