Anomalies in Daily Anisotropy During the Transition Period of Solar Cycles 24 and 25
DOI:
https://doi.org/10.53469/jrse.2025.07(01).03Keywords:
Cosmic rays, Diurnal anisotropy, Solar polar magnetic field, Polarity ReversalAbstract
The behavior of the diurnal variability of cosmic rays during the transition period of solar cycles 24 and 25 have been investigated in the present study. Cosmic ray anisotropy exhibited a characteristic feature from 2018 to 2021 at the end of solar activity cycle 24 and the beginning of solar cycle 25; characterized by a remarkably reduced diurnal amplitude and an unconventional low - phase distribution. Observations were carried out using data from eight neutron monitors with 2.0 to 7.0 GV cut - off rigidity over a long period of five and a half solar cycles. Significant discrepancies were observed in the amplitude and phase of the first harmonic of cosmic ray variation. The GCR modulation during solar minima 24/25 differs significantly from previous solar minima in several respects, particularly in terms of the low number of sunspots, weak interplanetary magnetic fields, and turbulence. According to the analysis, this anomaly is observed throughout various rigidities and latitudes, implying a global impact.
References
F. B. McDonald, W. R. Webber, and D. V. Reames, “Unusual time histories of galactic and anomalous cosmic rays at 1 AU over the deep solar minimum of cycle 23/24, ” Geophysics Res Lett, vol.37, no.18, Sep.2010, doi: 10.1029/2010GL044218.
A. Tezari and H. Mavromichalaki, “Diurnal anisotropy of cosmic rays during intensive solar activity for the period 2001 - 2014, ” New Astronomy, vol.46, pp.78– 84, Jul.2016, doi: 10.1016/j. newast.2015.12.008.
A. K. Tiwari, A. Singh, and S. P. Agrawal, “Study of the Diurnal Variation of Cosmic Rays during Different Phases of Solar Activity, ” Sol Phys, vol.279, no.1, pp.253–267, Jul.2012, doi: 10.1007/s11207 - 012 - 9962 - 3.
J. A. Van Allen, “On the modulation of galactic cosmic ray intensity during solar activity cycles 19, 20, 21, 22 and early 23, ” Geophysics Res Lett, vol.27, no.16, pp.2453–2456, Aug.2000, doi: 10.1029/2000GL003792.
E. H. Park, J. Jung, S. Oh, and P. Evenson, “Solar Cyclic Modulation of Diurnal Variation in Cosmic Ray Intensity, ” Journal of Astronomy and Space Sciences, vol.35, no.4, pp.219–225, Dec.2018, doi: 10.5140/JASS.2018.35.4.219.
V. K. Mishra and A. P. Mishra, “Study of solar activity and cosmic ray modulation during solar cycle 24 in comparison to previous solar cycle, ” Indian Journal of Physics, vol.90, no.12, pp.1333–1339, Dec.2016, doi: 10.1007/s12648 - 016 - 0895 - 9.
A. A. Pacini and I. G. Usoskin, “An Unusual Pattern of Cosmic - Ray Modulation During Solar Cycles 23 and 24, ” Sol Phys, vol.290, no.3, pp.943–950, Mar.2015, doi: 10.1007/s11207 - 014 - 0645 - 0.
R. Modzelewska, K. Iskra, W. Wozniak, M. Siluszyk, and M. V. Alania, “Features of the Galactic Cosmic Ray Anisotropy in Solar Cycle 24 and Solar Minima 23/24 and 24/25, ” Sol Phys, vol.294, no.10, Oct.2019, doi: 10.1007/s11207 - 019 - 1540 - 5.
F. Rahmanifard et al., “Evidence from Galactic Cosmic Rays That the Sun Has Likely Entered a Secular Minimum in Solar Activity, ” Space Weather, vol.20, no.2, Feb.2022, doi: 10.1029/2021SW002796.
A. A. Pacini and I. G. Usoskin, “An Unusual Pattern of Cosmic - Ray Modulation During Solar Cycles 23 and 24, ” Sol Phys, vol.290, no.3, pp.943–950, Mar.2015, doi: 10.1007/s11207 - 014 - 0645 - 0.
O. P. M. Aslam and Badruddin, “Study of Cosmic - Ray Modulation During the Recent Unusual Minimum and Mini - Maximum of Solar Cycle 24, ” Sol Phys, vol.290, no.8, pp.2333–2353, Aug.2015, doi: 10.1007/s11207 - 015 - 0753 - 5.
“Solar cycle 23, ” https: //en. wikipedia. org/wiki/Solar_cycle_23.
S. Basu, “The peculiar solar cycle 24 – where do we stand?” J Phys Conf Ser, vol.440, p.012001, Jun.2013, doi: 10.1088/1742 - 6596/440/1/012001.
K. Kudela and I. Sabbah, “Quasi - periodic variations of low energy cosmic rays, ” Sci China Techno Sci, vol.59, no.4, pp.547–557, Apr.2016, doi: 10.1007/s11431 - 015 - 5924 - y.
O. P. M. Aslam and Badruddin, “Solar Modulation of Cosmic Rays during the Declining and Minimum Phases of Solar Cycle 23: Comparison with Past Three Solar Cycles, ” Sol Phys, vol.279, no.1, pp.269–288, Jul.2012, doi: 10.1007/s11207 - 012 - 9970 - 3.
M. V Alania, R. G. Aslamazashvili, T. B. Bochorishvili’, K. Iskra’, and M. Siluszyk’, “The role of drift on the diurnal anisotropy and on temporal changes in the energy spectra of the ll - year variation for galactic cosmic rays, ” 2001, Adv. Space Res.
Vol.27, No.3, pp.613 - 618, 2001
M. Singh and Badruddin, “Study of the cosmic ray diurnal anisotropy during different solar and magnetic conditions, ” Sol Phys, vol.233, no.2, pp.291–317, Feb.2006, doi: 10.1007/s11207 - 006 - 2050 - 9.
W. Wozniak, K. Iskra, R. Modzelewska, and M. Siluszyk, “Analysis of Galactic Cosmic Ray Anisotropy During the Time Period from 1996 to 2020, ” Sol Phys, vol.298, no.2, Feb.2023, doi: 10.1007/s11207 - 023 - 02120 - x.
Kumar, Santosh, Rekha Agarwal, Rajesh Mishra, and
S. K. Dubey. "Daily variation in cosmic ray intensity on different geomagnetic conditions. " 2002, International Journal of Modern Physics D 11, no.08 (2002): 1243 - 1253.
S. Fu, X. Zhang, L. Zhao, and Y. Li, “Variations of the Galactic Cosmic Rays in the Recent Solar Cycles, ” Astrophysics J Suppl Ser, vol.254, no.2, p.37, Jun.2021, doi: 10.3847/1538 - 4365/abf936.
Z. Kobylinski, A. Wysokinski, and T. Seredyn, “Neural network forecast of the solar, geomagnetic activity and cosmic ray intensity during 25 cycle, ” 2019. Preceding of science
U. Okiyi, K. C. Okpala, J. O. Tsor, and F. Egbunu, “Variability of quiet - time diurnal amplitude and phase of cosmic ray count rates in the mid - and high latitudes, ” International Journal of Physical Sciences, vol.12, no.22, pp.295–307, Nov.2017, doi: 10.5897/ijps2017.4676.
E. A. Brunberg and A. Dattner, “On the Interpretation of the Diurnal Variation of Cosmic Rays, ” Tellus, vol.6, no.1, pp.73–83, Jan.1954, doi: 10.3402/Tellus. v6i1.8705.
I. V. Dorman and L. I. Dorman, “Propagation of energetic particles through interplanetary space according to the data of 11 - yr cosmic ray variations, ” Journal of Atmospheric and Terrestrial Physics, vol.29, no.4, pp.429–447, Apr.1967, doi: 10.1016/0021 - 9169 (67) 90025 - 6.
U. R. Rao, K. G. McCracken, and D. Venkatesan, “Asymptotic cones of acceptance and their use in the study of the daily variation of cosmic radiation, ” J Geophys Res, vol.68, no.2, pp.345–369, Jan.1963, doi: 10.1029/JZ068i002p00345.
K. G. McCracken, & U. R. Rao, “A survey of the diurnal anisotropy”, Proceedings of the 9th International Cosmic Ray Conference, Vol.1, p.213
H. S. Ahluwalia, and J. H. Ericksen. "Solar diurnal variations of cosmic ray intensity underground during solar activity Cycle - 20. " In Proceedings of the 11th International Conference on Cosmic Rays, held in Budapest, 25 August - 4 September, 1969. Edited by A. Somogyi, Vol.2. Acta Physica, Supplement to Volume
Solar Cosmic Rays, Modulation of Galactic Radiation, Magnetospheric and Atmospheric Effects., p.139, vol.2, p.139.1970.
E. V. Kolomeets, “Periodic cosmic ray variations and their change during the cycle of solar activity, ” in Proceedings of the 9th International Cosmic Ray Conference, 1965, p.224.
M. A. POMERANTZ and S. P. DUGGAL “The cosmic ray solar diurnal anisotropy, ” 1971, Space Science Reviews 12 (1971) 75 - 130.
John W. Bieber, and Jiasheng Chen. "Cosmic - ray diurnal anisotropy, 1936 - 1988 - Implications for drift and modulation theories. " Astrophysical Journal, Part 1 (ISSN 0004 - 637X), vol.372, May 1, 1991, p.301 - 313.372 (1991): 301 - 313.
M. A. El - Borie, I. S. Sabbah, and A. A. Bishara, “Diurnal variations of cosmic rays during a solar magnetic cycle, ” Astronomische Nachrichten, vol.317, no.4, pp.267–272, 1996, doi: 10.1002/asna.2113170405.
A. Tezari et al., “Latitudinal and longitudinal dependence of the cosmic ray diurnal anisotropy during 2001–2014, ” Ann Geophys, vol.34, no.11, pp.1053–1068, Nov.2016, doi: 10.5194/angeo - 34 - 1053 - 2016.
A. Singh, A. K. Tiwari, and S. P. Agrawal, “Study of the diurnal variation of cosmic rays during different phases of solar activity, ” in Proceedings of the 32nd International Cosmic Ray Conference, ICRC 2011, Institute of High Energy Physics, 2011, pp.120–132. doi: 10.7529/ICRC2011/V06/0072.
N. K. Sharma, “On the cosmic ray response to coronal high - speed solar wind streams, ” Indian Journal of Physics., 1996.
P. Väisänen, I. Usoskin, and K. Mursula, “Seven Decades of Neutron Monitors (1951–2019): Overview and Evaluation of Data Sources, ” J Geophys Res Space Phys, vol.126, no.5, May 2021, doi: 10.1029/2020JA028941.
A. V. Belov, R. T. Gushchina, V. N. Obridko, B. D. Shelting, and V. G. Yanke, “Long - term variations of galactic cosmic rays in the past and future from observations of various solar activity characteristics, ” J Atmos Sol Terr Phys, vol.68, no.11, pp.1161–1166, Jul.2006, doi: 10.1016/j. jastp.2006.01.001.
M. Singh and Badruddin, “Study of the Cosmic Ray Diurnal Anisotropy During Different Solar and Magnetic Conditions, ” Sol Phys, vol.233, no.2, pp.291–317, Feb.2006, doi: 10.1007/s11207 - 006 - 2050 - 9.
V. G. Yanke, A. V. Belov, and R. T. Gushchina, “Long
- Term Modulation of Cosmic Rays in Solar Cycles 23–24, ” Bulletin of the Russian Academy of Sciences: Physics, vol.85, no.9, pp.1045–1048, Sep.2021, doi: 10.3103/S1062873821090355.
S. Fu, X. Zhang, L. Zhao, and Y. Li, “Variations of the Galactic Cosmic Rays in the Recent Solar Cycles, ” Astrophys J Suppl Ser, vol.254, no.2, p.37, Jun.2021, doi: 10.3847/1538 - 4365/abf936.
V. G. Yanke, A. V. Belov, and R. T. Gushchina, “Variations of Cosmic Rays with Various Energies in the Minima of Solar Activity Cycles, ” Geomagnetism and Aeronomy, vol.62, no.4, pp.347–355, Aug.2022, doi: 10.1134/S001679322204017X.
V Yanke, A Belov, R Gushchina “Long - Term Modulation of Cosmic Rays in Solar Cycles 23– 24”, Bulletin of the Russian Academy of Sciences: Physics (2021) 85 (9) 1045 - 104
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