Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

On the Interaction of Galactic Cosmic Rays with Heliospheric Shocks During Forbush Decreases


Forbush decreases (FDs) are depletions in the galactic cosmic ray (GCR) count rate that last typically for about a week and can be caused by coronal mass ejections (CMEs) or corotating interacting regions (CIRs). Fast CMEs that drive shocks cause large FDs that often show a two-step decrease where the first step is attributed to the shock/sheath region, while the second step is attributed to the closed magnetic structure. Since the difference in size of shock and sheath region is significant, and since there are observed effects that can be related to shocks and not necessarily to the sheath region we expect that the physical mechanisms governing the interaction with GCRs in these two regions are different. We therefore aim to analyze interaction of GCRs with heliospheric shocks only. We approximate the shock by a structure where the magnetic field linearly changes with position within this structure. We assume protons of different energy, different pitch angle and different incoming direction. We also vary the shock parameters such as the magnetic field strength and orientation, as well as the shock thickness. The results demonstrate that protons with higher energies are less likely to be reflected. Also, thicker shocks and shocks with stronger field reflect protons more efficiently.

This is a preview of subscription content, log in to check access.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8


  1. Badruddin, Kumar, A.: 2016, Study of the cosmic-ray modulation during the passage of ICMEs and CIRs. Solar Phys.291, 559. DOI . ADS .

  2. Belov, A.V.: 2009, Forbush effects and their connection with solar, interplanetary and geomagnetic phenomena. In: Gopalswamy, N., Webb, D.F. (eds.) Universal Heliophysical Processes, IAU Symposium257, 439. DOI . ADS .

  3. Belov, A.V., Dorman, L.I., Eroshenko, E.A., Iucci, N., Villoresi, G., Yanke, V.G.: 1995, Search for predictors of Forbush decreases. In: International Cosmic Ray Conference, 4, 888. ADS .

  4. Belov, A.V., Eroshenko, E.A., Oleneva, V.A., Struminsky, A.B., Yanke, V.G.: 2001, What determines the magnitude of Forbush decreases? Adv. Space Res.27, 625. DOI . ADS .

  5. Cane, H.V.: 1993, Cosmic ray decreases and magnetic clouds. J. Geophys. Res.98, 3509. DOI . ADS .

  6. Cane, H.V.: 2000, Coronal mass ejections and Forbush decreases. Space Sci. Rev.93, 55. DOI . ADS .

  7. Cane, H.V., Richardson, I.G., Wibberenz, G.: 1995, The response of energetic particles to the presence of ejecta material. In: International Cosmic Ray Conference4, 377. ADS .

  8. Desai, M., Giacalone, J.: 2016, Large gradual solar energetic particle events. Living Rev. Solar Phys.13(1), 3. DOI . ADS .

  9. Dumbović, M., Vršnak, B., Čalogović, J., Karlica, M.: 2011, Cosmic ray modulation by solar wind disturbances. Astron. Astrophys.531, A91. DOI . ADS .

  10. Dumbović, M., Vršnak, B., Čalogović, J., Župan, R.: 2012, Cosmic ray modulation by different types of solar wind disturbances. Astron. Astrophys.538, A28. DOI . ADS .

  11. Dumbović, M., Heber, B., Vršnak, B., Temmer, M., Kirin, A.: 2018, An analytical diffusion-expansion model for Forbush decreases caused by flux ropes. Astrophys. J.860, 71. DOI . ADS .

  12. Forbush, S.E.: 1937, On the effects in cosmic-ray intensity observed during the recent magnetic storm. Phys. Rev.51, 1108. DOI . ADS .

  13. Giacalone, J.: 2004, Large-scale hybrid simulations of particle acceleration at a parallel shock. Astrophys. J.609(1), 452. DOI . ADS .

  14. Hess, V.F., Demmelmair, A.: 1937, World-wide effect in cosmic ray intensity, as observed during a recent magnetic storm. Nature140, 316. DOI . ADS .

  15. Kilpua, E., Koskinen, H.E.J., Pulkkinen, T.I.: 2017, Coronal mass ejections and their sheath regions in interplanetary space. Living Rev. Solar Phys.14, 5. DOI . ADS .

  16. Krymsky, G.F., Krivoshapkin, P.A., Mamrukova, V.P., Gerasimova, S.K.: 2009, Piston shock and Forbush effect. Astron. Lett.35, 696. DOI . ADS .

  17. Le Roux, J.A., Potgieter, M.S.: 1991, The simulation of Forbush decreases with time-dependent cosmic-ray modulation models of varying complexity. Astron. Astrophys.243, 531. ADS .

  18. Lingri, D., Mavromichalaki, H., Belov, A., Abunina, M., Eroshenko, E., Abunin, A.: 2019, An extended study of the precursory signs of Forbush decreases: new findings over the years 2008 – 2016. Solar Phys.294(6), 70. DOI . ADS .

  19. Lockwood, J.A.: 1971, Forbush decreases in the cosmic radiation. Space Sci. Rev.12, 658. DOI .

  20. Lockwood, J.A., Webber, W.R., Jokipii, J.R.: 1986, Characteristic recovery times of Forbush-type decreases in the cosmic radiation. I – Observations at Earth at different energies. J. Geophys. Res.91, 2851. DOI . ADS .

  21. Melkumyan, A.A., Belov, A.V., Abunina, M.A., Abunin, A.A., Eroshenko, E.A., Yanke, V.G., Oleneva, V.A.: 2019, Comparison between statistical properties of Forbush decreases caused by solar wind disturbances from coronal mass ejections and coronal holes. Adv. Space Res.63(2), 1100. DOI . ADS .

  22. Munakata, K., Yasue, S., Kato, C., Kota, J., Tokumaru, M., Kojima, M., Darwish, A.A., Kuwabara, T., Bieber, J.W.: 2006, On the cross-field diffusion of galactic cosmic rays into an ICME. Solar Terrestrial (ST), Advances in Geosciences2, 115. DOI . ADS .

  23. Papailiou, M., Mavromichalaki, H., Belov, A., Eroshenko, E., Yanke, V.: 2012, Precursor effects in different cases of Forbush decreases. Solar Phys.276(1–2), 337. DOI . ADS .

  24. Parker, E.N.: 1961, Sudden expansion of the corona following a large solar flare and the attendant magnetic field and cosmic-ray effects. Astrophys. J.133, 1014. DOI . ADS .

  25. Pinter, S.: 1980, The thickness of interplanetary collisionless shock waves. Bull. Astron. Inst. Czechoslov.31, 368. DOI . ADS .

  26. Quenby, J.J., Mulligan, T., Blake, J.B., Mazur, J.E., Shaul, D.: 2008, Local and nonlocal geometry of interplanetary coronal mass ejections: Galactic cosmic ray (GCR) short-period variations and magnetic field modeling. J. Geophys. Res.113, A10102. DOI . ADS .

  27. Richardson, I.G.: 2004, Energetic particles and corotating interaction regions in the solar wind. Space Sci. Rev.111, 267. DOI . ADS .

  28. Richardson, I.G., Cane, H.V.: 2011, Galactic cosmic ray intensity response to interplanetary coronal mass ejections/magnetic clouds in 1995–2009. Solar Phys.270(2), 609. DOI . ADS .

  29. Russell, C.T., Mulligan, T.: 2002, On the magnetosheath thicknesses of interplanetary coronal mass ejections. Planet. Space Sci.50, 527. DOI . ADS .

  30. Stone, R.G., Tsurutani, B.T. (eds.): 1985, Collisionless Shocks in the Heliosphere: A Tutorial Review, Geophysical Monograph Series34, American Geophysical Union, Washington. DOI . ADS .

  31. Subramanian, P., Antia, H.M., Dugad, S.R., Goswami, U.D., Gupta, S.K., Hayashi, Y., Ito, N., Kawakami, S., Kojima, H., Mohanty, P.K., Nayak, P.K., Nonaka, T., Oshima, A., Sivaprasad, K., Tanaka, H., Tonwar, S.C. (The Grapes-3 Collaboration): 2009, Forbush decreases and turbulence levels at coronal mass ejection fronts. Astron. Astrophys.494, 1107. DOI . ADS .

  32. Wawrzynczak, A., Alania, M.V.: 2010, Modeling and data analysis of a Forbush decrease. Adv. Space Res.45, 622. DOI . ADS .

  33. Wibberenz, G., Le Roux, J.A., Potgieter, M.S., Bieber, J.W.: 1998, Transient effects and disturbed conditions. Space Sci. Rev.83, 309. ADS .

Download references


BV and MD acknowledge a support by the Croatian Science Foundation under the project 7549 “Millimeter and submillimeter observations of the solar chromosphere with ALMA”. The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 745782 (ForbMod).

Author information

Correspondence to Anamarija Kirin or Bojan Vršnak.

Ethics declarations

Disclosure of Potential Conflicts of Interest

The authors declare that they have no conflicts of interest.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kirin, A., Vršnak, B., Dumbović, M. et al. On the Interaction of Galactic Cosmic Rays with Heliospheric Shocks During Forbush Decreases. Sol Phys 295, 28 (2020). https://doi.org/10.1007/s11207-020-1593-5

Download citation


  • Cosmic rays, galactic
  • Magnetic fields, models
  • Waves, magnetohydrodynamic, shock
  • Coronal mass ejections