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Research Paper | Physics | Nigeria | Volume 12 Issue 6, June 2023
The Influence of Magnetic Flux Rope Events on Galactic Cosmic Ray Anisotropy
G. Adagba [4] | B. A. Ikyo [3]
Abstract: Galactic cosmic ray anisotropy inferred from ground-based observations during Forbush decrease events can provide very useful information on the local plasma and magnetic field structures such as the magnetic field structures of an interplanetary coronal mass ejection (ICME). This is because galactic cosmic ray distribution allows remote sensing of distant conditions. Here, we studied GCR anisotropy for two (2) flux rope events; February 2011 and March 2013 events with an aim to compare anisotropy features of the two events. Our results showed that for both events; FD of February 2011 and FD of April 2013 at times with strong magnetic fluctuations and strong cosmic-ray scattering, there were spikes of high perpendicular anisotropy and weak parallel anisotropy. These results, along with the near constancy of parallel anisotropy across magnetic field reversals, are consistent with diffusive barriers causing the decrease in GCR flux before the arrival of the flux rope. In contrast, within the CME flux rope there was a strong parallel anisotropy in the direction predicted from a theory of drift motions into one leg of the magnetic flux rope and out the other. This result confirm that FD events associated with flux ropes can influence GCR flux in a similar way.
Keywords: cosmic rays - Sun: coronal mass ejections (CMEs) - turbulence
Edition: Volume 12 Issue 6, June 2023,
Pages: 1 - 6