Cosmic ray density gradients related to north-south asymmetry in activity on the sun

Journal Article · Sat Mar 01 04:00:00 EST 1986 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA091iA03p02943· OSTI ID:5875546

Swinson, D B; Shea, M A; Humble, J E

Data are presented from underground cosmic ray telescopes in both the northern and southern hemisphere from 1965 to 1983, analyzed as a function of interplanetary magnetic field (IMF) sense, to examine the long-term properties of the cosmic ray density gradient perpendicular to the ecliptic plane, delN/sub p/. Yearly cosmic ray solar diurnal variation vectors for IMF (B) away from and toward the sun are obtained; these vectors include a contribution from the B x delN/sub p/ anisotropy, from which the predominant direction of the perpendicular gradient, delN/sub p/, is inferred. These data are compared with the north-south asymmetry in activity on the sun for the same period, based both on comprehensive flare index data and on solar events associated with type II radio emission. The cosmic ray data up to the 1969-1971 solar polar field reversal are consistent with a perpendicular cosmic ray gradient pointing southward, observed by telescopes in both hemispheres. The solar activity data indicate a statistically significant excess of activity in the sun's northern hemisphere from 1959 through 1970, which may well be the cause for this southward perpendicular cosmic ray gradient during this period. After the 1969-1971 reversal the solar activity data become reasonably symmetrically divided between the two solar hemispheres. The northern hemisphere cosmic ray data show some evidence of a northward pointing cosmic ray gradient after 1971, while data from the southern hemisphere telescopes continue to indicate a southward pointing gradient.

• Research Organization: Department of Physics and Astronomy, The University of New Mexico, Albuquerque
• OSTI ID: 5875546
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 91:A3; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR CORRELATION
CORRELATIONS
COSMIC RADIATION
DAILY VARIATIONS
INTERPLANETARY MAGNETIC FIELDS
IONIZING RADIATIONS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELD REVERSAL
MAGNETIC FIELDS
RADIATIONS
SOLAR ACTIVITY
SPACE DEPENDENCE
TELESCOPES
TENSORS
VARIATIONS
VECTORS