Yakutsk, Russian Federation
Yakutsk, Yakutsk, Russian Federation
Yakutsk, Yakutsk, Russian Federation
Yakutsk, Yakutsk, Russian Federation
The work studies the cumulative modulating effect of the geometry of the interplanetary magnetic field's neutral current sheet and solar activity on propagation of galactic cosmic rays in the heliosphere. The role of each factor on the modulation of cosmic rays is estimated using a method of main components. The application of the method to experimental data on solar activity, to the tilt angle of the neutral sheet, and cosmic ray intensity for a long period from 1980 to 2018 allows us to reveal the temporal dynamics of roles of these factors in the modulation. The modulation character is shown to strongly depend on the polarity of the Sun’s general magnetic field. Results of the study confirm the existing theoretical concepts of the heliospheric modulation of cosmic rays and reflect its peculiarities for almost four full cycles of solar activity.
cosmic ray modulation, interplanetary magnetic field, neutral current sheet, solar activity
1. El-Borie M.A., Hamdy A. A correlative study between heliospheric current sheet tilts, cosmic ray intensities and solar activity parameters. Arab J. Nucl. Sci. Appl. 2018, vol. 51, no. 1, pp. 152-167.
2. Burger R.A. Modeling drift along the heliospheric wavy neutral sheet. The Astrophys. J. 2012, vol. 760, no 1, pp.1-5. DOI:https://doi.org/10.1088/0004-637X/760/1/60.
3. Gupta M., Mishra V.K., Mishra A.P. Cosmic ray intensity associated with sunspot numbers and tilt angle. Indian J. Phys. 2006, vol. 80, no. 7, pp. 697-701.
4. Gushchina R.T., Belov A.V., Eroshenko E.A., Obridko V.N., Paouris E., Shelting B.D. Cosmic ray modulation during the solar activity growth phase of cycle 24. Geomagnetism and Aeronomy. 2014, vol. 54, iss. 4, pp. 430-436. DOI:https://doi.org/10.1134/S0016793214040057.
5. Ishkov V.N. Reduced and extended periods of solar activity: monitoring features and key facts. Vserossiiskaya ezhegodnaya konferentsiya po fizike Solntsa “Solnechnaya i solnechno-zemnaya fizika - 2013”: Trudy [Proc. Russian National Annual Conference on Solar Physics “Solar and Solar-Terrestrial Physics - 2013”] Saint-Peretsburg, 2013, pp. 111-114. (In Russian).
6. Ishkov V.N. Space weather and specific features of the development of current solar cycle. Geomagnetism and aeronomy. 2018, vol. 58, no. 6, pp. 753-767. DOI: 10.1134/ S0016793218060051.
7. Iskra K., Soluszyk M., Alania M., Wozniak W. Experimental investigation of the delay time in galactic cosmic ray flux in different epochs of solar magnetic cycles: 1959-2014. Solar Phys. 2019, vol. 294, iss. 9, article id. 115, 14 p. DOI:https://doi.org/10.1007/s11207-019-1509-4.
8. Kota J., Jokipii J.R. Effects of drift on the transport of cosmic rays. VI. A three-dimentional model including diffusion. The Astrophys. J. 1983, vol. 265, pp. 573-581.
9. Krainev M.B. Characteristics of the heliosphere important for galactic cosmic rays in the phase of minimal solar activity // Kratkie soobshcheniya po fizike FIAN [Brief Information on Physics by Lebedev Physical Institute RAS]. 2012, no. 6, pp. 13-20. (In Russian).
10. Krainev M.B., Kalinin M.S. On the structure of galactic cosmic ray intensity during its long-term variations. Bull. of the Russian Academy of Sciences: Physics. 2013, vol. 77, no. 5, pp. 510-512. DOI:https://doi.org/10.3103/S1062873813050316.
11. Krymsky G.F., Krivoshapkin P.A., Gerasimova S.K., Grigoryev V.G., Mamrukova V.P. Modulation of cosmic rays by the heliospheric neutral sheet. Geomagnetizm i ajeronomija [Geomagnetizm and Aeronomy]. 2001a, vol. 41, no. 4, pp. 444-449. (In Russian).
12. Krymsky G.F., Krivoshapkin P.A., Gerasimova S.K., Grigoryev V.G., Mamrukova V.P. Neutral sheet and drift of particles in long-period cosmic rays variations. Izvestiya RAN. Ser. fizicheskaya [Bull. of the Russian Academy of Sciences: Physics]. 2001b, vol. 65, no. 3, pp. 353-355. (In Russian).
13. Krymsky G.F., Krivoshapkin P.A., Gerasimova S.K., Grigoryev V.G., Mamrukova V.P. Deformation of the heliospheric current sheet as a reason of long-term cosmic ray variations. Proc. 27th ICRC 2001. Hamburg. Germany. 2001, pp. 3871-3873.
14. Mavromichalaki H., Paouris E., Karalidi T. Cosmic-ray modulation: an empirical relation with solar and heliospheric parameters. Solar Phys. 2007, vol. 245, pp. 369-390. DOI:https://doi.org/10.1007/s11207-007-9043-1.
15. Paouris E., Mavromichalaki H., Belov A., Gushchina R.T. Galactic cosmic ray modulation and the last solar minimum. Solar Phys. 2012, vol. 280, pp. 255-271. DOI: 10.1007/ s11207-012-0051-4.
16. Potgieter M.S., Moraal H. A drift model for the modulation of galactic cosmic rays. The Astrophys. J. 1985, vol. 294, pp. 425-440.
17. Reinecke L.J.P., Potgieter S.M., van Staden I.M. The neutral sheet tilt dependence of cosmic ray neutron monitor intensities at different cutoff rigidities. Proc. 21st ICRC. Adelaide. Australia. 1990, vol. 6, pp. 95-98.
18. Smith E.J., Thomas B.T. Latitudinal extent of the heliospheric current sheet and modulation of galactic cosmic rays. J. Geophys. Res. 1986. vol. 91, no. A3. P. 2933-2942. DOI:https://doi.org/10.1029/JA091iA03p02933.
19. Usoskin I.G., Kananen H., Mursula K., Tanskanen P., Kovaltsov G.A. Correlative study of solar activity and cosmic ray intensity. J. Geophys. Res. 1998, vol. 103, no. 5, pp. 9567-9574. DOI:https://doi.org/10.1029/97JA03782.
20. Tomassetti N., Orcinha M., Barão F., Bertucci B. Evidence for a time lag in solar modulation of galactic cosmic rays. The Astrophys. J. Lett. 2017, vol. 849, no. L32, 6 p. DOI:https://doi.org/10.3847/2041-8213/aa9373.
21. Zhao L.-L., Qin G., Zang M., Heber B. Modulation of galactic cosmic ray during the unusual solar minimum between cycles 23 and 24. J. Geophys. Res.: Space Phys. 2014, vol. 119, iss. 3, pp. 1493-1506. DOI:https://doi.org/10.1002/2013JA019550.
22. URL: http://wso.stanford.edu/gifs/Tilts.gif (accessed November 11, 2019).
23. URL: http://www.sidc.be/silso/DATA/SN_m_tot_V2.0.txt (accessed November 11, 2019).
24. URL: https://cosmicrays.oulu.fi (accessed November 11, 2019).
