Variations of three-dimensional anisotropy of cosmic rays during Forbush decreases

Journal Article · Mon Oct 01 04:00:00 EDT 1973 · J. Geophys. Res., v. 78, no. 28, pp. 6409-6427

DOI:https://doi.org/10.1029/JA078i028p06409· OSTI ID:4349169

Yoshida, S; Ogita, N; Akasofu, S; Gleeson, L J

Variations of three-dimensional anisotropy of cosmic rays during Forbush decresses are examined by a spherical harmonic method and by constructing successive isointensity contour maps in the solar ecliptic coordinate system. The east-west and north-south anisotropies are studied statistically and for several individual events; the data are based on cosmic ray records from about 24 stations for the 3-year peried from 1966 to 1968. For the individual events the high anisotropies of ~4% are examined in terins of the convective, diffusive, and density gradient components of the differential streaming as well as the interplanetary magnetic field and solar wind. In each case, vector gradients are derived that lead to the observed anisotropies, and the magnitude of these gradients is typically 10-20 times that of the quiet time interplanetary gradient. (auth)

• Research Organization: Geophysical Institute, University of Alaska, Fairbanks, Alaska, 99701
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-021728
• OSTI ID: 4349169
• Journal Information: J. Geophys. Res., v. 78, no. 28, pp. 6409-6427, Journal Name: J. Geophys. Res., v. 78, no. 28, pp. 6409-6427; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

*COSMIC RADIATION-- FORBUSH DECREASE
ANGULAR CORRELATION
ANISOTROPY
N56100* --Physics (Astrophysics & Cosmology)--Cosmic Radiation
NEUTRONS
VARIATIONS