27-Day Variations in Cosmic Rays During the Ascending and Descending Phase of the 24th Solar Activity Cycle

Authors

  • George K. Vanishvili M. Nodia Institute of Geophysics of I. Javakhishvili Tbilisi State University; Sokhumi State University
  • Teimuraz S. Bakradze M. Nodia Institute of Geophysics of I. Javakhishvili Tbilisi State University
  • Eteri M. Alania M. Nodia Institute of Geophysics of I. Javakhishvili Tbilisi State University
  • Tereza G. Erkomaishvili M. Nodia Institute of Geophysics of I. Javakhishvili Tbilisi State University
  • Vitali G. Kavlashvili M. Nodia Institute of Geophysics of I. Javakhishvili Tbilisi State University
  • Mariam G. Gugunashvili Sokhumi State University
  • Omar E. Khajishvili Sokhumi State University

Keywords:

Cosmic ray 27- day variations, Solar Cycle, Bartels Rotation Number, Carrington Rotation Number, Solar Activity ascending & descending phase, World -Wide Network of cosmic ray neutron monitors, quasisinusiudal curve

Abstract

Based on the study of the 27-day variations of the neutron component of cosmic rays at two stations of the Global Cosmic Ray Network (Moscow and Yakutsk) and the Tbilisi Cosmophysical Observatory in the ascending and descending phases of the 24th cycle of solar activity, it has been established that the 27-day variation profile describes a quasi-sinusoidal curve. The deviation from the sinusoidal curve is determined by the change in the number, coordinates and power of sunspots (2.2 in the ascending phase and 81.8 in the descending phase) in a given phase of solar activity.

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Published

2026-08-21

How to Cite

Vanishvili, G. K., Bakradze, T. S., Alania, E. M., Erkomaishvili, T. G., Kavlashvili, V. G., Gugunashvili, M. G., & Khajishvili, O. E. (2026). 27-Day Variations in Cosmic Rays During the Ascending and Descending Phase of the 24th Solar Activity Cycle. Journals of Georgian Geophysical Society, 29(1), 90–97. Retrieved from https://ggs.openjournals.ge/index.php/GGS/article/view/12096

Issue

Vol. 29 No. 1 (2026): Physics of Solid Earth, Atmosphere, Ocean and Space Plasma

Section

Articles