Average Anisotropy Characteristics of High Energy Cosmic Ray Particles and Geomagnetic Disturbance Index Ap

Journal of astrophysics and astronomy

Pankaj K. Shrivastava2¹  Ajay K. Pandey²  C. M. Tiwari1²  D. P. Tiwari² 

[1] Department of Physics, Govt. Model Science College, Rewa (MP) 486 001, India.$$;Department of Physics, A.P.S. University, Rewa (MP) 486 003, India.$$

关键词: Cosmic rays;    anisotropic variation;    geomagnetic disturbances.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The average characteristics of the diurnal and semi-diurnal anisotropy of cosmic ray intensity at relativistic energies have been obtained by using data from the worldwide grid of neutron monitor for the period 1989 to 1996. The complex behaviour of the diurnal amplitudes and time of maxima (phase) and its association with the Ap index on a long-term and day-to-day basis have been studied. Even though the general characteristics, on a yearly average basis, have not changed significantly during this period, both the diurnal and semi-diurnal amplitudes and phases vary significantly, besides significant changes being observed for different interplanetary conditions on a short-term basis. It is found that the relationship between the Ap index and the diurnal vector is out of phase during the period 1991 to 1995. On a long-term basis, the correlation of diurnal variation with Ap index has been found to vary during the solar cycle. On a short-term basis, it has been observed that the high Ap days are usually associated with higher amplitudes with phase shifted to earlier hours.

【 授权许可】

Unknown