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      Permanent link:
      https://www.ias.ac.in/article/fulltext/joaa/031/02/0089-0096

    • Keywords

       

      Cosmic rays; diurnal variation; high amplitude anisotropic events; low amplitude anisotropic events; solar cycle; solar wind speed.

    • Abstract

       

      A detailed study has been conducted on the long-term changes in the diurnal variation of cosmic rays in terms of high and low amplitude wave trains event (HAEs/LAEs) during the period 1996–2008 (solar cycle 23), using the neutron monitor data from Kiel neutron monitoring station. As such, 17 HAE and 48 LAE cases have been detected and analyzed. These HAEs appear quite dominantly during the declining phase as well as near the maximum of the solar activity cycle 23. In contrast, the low amplitude events (LAEs) are inversely correlated with solar activity cycle. In fact, LAEs appear quite dominantly during the minimum phase of the solar activity. When we compare our results for diurnal phase with that observed on an annual average basis, we notice no significant diurnal phase shift for HAEs as well as for LAEs. Moreover, we find that the high-speed solar wind streams (HSSWS) do not play any significant role in causing these variations. These results are discussed on the basis of that observed in earlier cycles.

    • Author Affiliations

       

      Ambika Singh1 Anil Kumar Tiwari1 S. P. Agrawal2

      1. Physics Department, Government T.R.S. College, Rewa (M.P.) 486 001, India.
      2. Physics Department, A.P.S. University, Rewa (M.P.) 486 003, India.
    • Dates

       
  • Journal of Astrophysics and Astronomy | News

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