Quasi-periodic changes of three dimensional solar anisotropy of galactic cosmic rays for 1965-2014

Abstract

We study features of the three dimensional (3D) solar anisotropy of galactic cosmic rays (GCR) for 1965-2014 (almost 5 solar cycles 20-24). We analyze the 27-day variations of the two dimensional (2D) GCR anisotropy in the ecliptic plane, and the north-south anisotropy normal to the ecliptic plane. We study the dependence of the 27-day variation of the 3D GCR anisotropy on the solar cycle and solar magnetic cycle. We demonstrate that the 27-day variations of the GCR intensity and anisotropy can be used as an important tool to study solar wind, solar activity and heliosphere. We show that behavior of the 27-variation of the 3D anisotropy verifies an existence of a stable long-lived active heliolongitudes on the sun. This finding illustrates usefulness of the 27-day variation of the GCR anisotropy as a unique proxy to study solar wind, solar activity and heliosphere. We distinguish a tendency of the 22-year changes of the amplitudes of the 27-day variation of the 2D anisotropy connected with the solar magnetic cycle. We demonstrate that the amplitudes of the 27-day variation of the north-south component of the anisotropy vary upon the 11 year solar cycle, however, a dependence of the solar magnetic polarity hardly can be recognized. We show that the 27-day recurrences of the GG index and At component are in a high positive correlation, and both are highly correlated with By component of the heliospheric magnetic field.