Quasi-periodic changes of galactic cosmic ray anisotropy and intensity

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1Iskra, K, Gil, A, 2Modzelewska, R, Alania, MV
1Polish University of the Air Force, Deblin, Poland
2University of Natural Sciences and Humanities, Siedlce, Poland
Kinemat. fiz. nebesnyh tel (Online) 2006, 22(6):413-421
Language: English
Abstract: 

The 27-day variations of galactic cosmic ray (GCR) anisotropy and intensity are studied based on the neutron monitors data for the A > 0 and the A < 0 polarity periods of solar magnetic cycles (for the A > 0 polarity period of the solar magnetic cycle lines of the interplanetary magnetic field (IMF) are directed outward from the northern hemisphere, while for the A < 0 polarity period the opposite situation takes place). It is shown that the amplitudes of the 27-day variation of GCR anisotropy are greater in the A > 0 polarity period than in the A < 0 polarity period of the solar magnetic cycles being in good correlation with the similar changes of the amplitudes of the 27-day variation of GCR intensity. These changes in the amplitudes of the 27-day variations of galactic cosmic ray intensity and anisotropy are caused by the alternating radial component of the drift stream Sd of galactic cosmic rays in different polarity periods of the solar magnetic cycles. In the A > 0 polarity period the stream Sd is directed outward from the Sun, while in the A < 0 polarity period of the solar magnetic cycle the stream Sd has vice versa direction.

Keywords: galactic cosmic rays