студент с 01.01.2019 по 01.01.2025
Москва, г. Москва и Московская область, Россия
студент с 01.01.2019 по 01.01.2025
Москва, Россия
Москва, Россия
Москва, Россия
Москва, Россия
Neutron monitors (NMs), located at different points on the planet, allow us to study the time, energy, and angular characteristics of galactic and solar particle fluxes. Since NMs are located inside Earth's magnetosphere, their response depends on their location on the planet's surface, which can be characterized by the geomagnetic cutoff rigidity. Its calculation depends on the magnetic field model, the date, and even on numerical methods. The paper presents calculated geomagnetic cutoff rigidities at the locations of some neutron monitors and compares the cutoff values with the calculation results obtained by other authors, including a comparison of the time dynamics over the past decade. We show that the geomagnetic cutoff rigidities obtained for 2020 by the IGRF-14 model differ from those derived by IGRF-13; however, for 2015 the difference between the models is negligible. We demonstrate a tendency for the geomagnetic cutoff rigidity to decrease over time, especially at midlatitudes. Comparison of the obtained geomagnetic cutoff rigidities with those obtained by other authors has shown that in most cases the difference does not exceed 0.2 GV. Such discrepancies are significant only in the circumpolar region, where particles are mostly shielded by Earth’s atmosphere rather than by the geomagnetic field. We show that the accuracy of the algorithm in use is comparable to that of other existing instruments and is sufficient for calculating neutron monitor responses.
geomagnetic field, geomagnetic cutoff rigidity, cosmic rays, neutron monitors
1. Abunina M.A., Belov A.V., Eroshenko E.A., et al. Ring of station method in research of cosmic ray variations: 1. General description. Geomagnetism and Aeronomy. 2020, vol. 60, no. 1, pp. 38–45. DOI:https://doi.org/10.1134/S0016793220010028.
2. Alken P., Thébault E., Beggan C.D., et al. International geomagnetic reference field: The thirteenth generation. Earth, Planets and Space. 2021, vol. 73, pp. 1–25. DOI:https://doi.org/10.1186/s40623-020-01288-x.
3. Boris J.P. The acceleration calculation from a scalar potential. Technical report MATT-152. Princeton: Princeton University, 1970, 30 р.
4. Boris J.P. Relativistic plasma simulation — optimization of a hybrid code. Proc. 4th Conf. on Numerical Simulation of Plasmas. Washington, 1971, p. 3.
5. Cooke D.J., Humble J.E., Shea M.A., et al. On cosmic-ray cut-off terminology. Nuovo Cimento C. 1991, vol. 14, pp. 213–234. DOI:https://doi.org/10.1007/BF02509357.
6. Gerontidou M., Katzourakis N., Mavromichalaki H., et al. World grid of cosmic ray vertical cut-off rigidity for the last decade. Adv. Space Res. 2021, vol. 67, no. 7, pp. 2231–2240. DOI:https://doi.org/10.1016/j.asr.2021.01.011.
7. Gvozdevsky B., Belov A., Gushchina R., et al. Long-term changes in vertical geomagnetic cutoff rigidities of cosmic rays. Physics of Atomic Nuclei. 2018, vol. 81, pp. 1382–1389. DOI:https://doi.org/10.1134/S1063778818090132.
8. Mao H., Wirz R.E. Comparison of charged particle tracking methods for non-uniform magnetic fields. 42nd AIAA Plasmadynamics and Lasers Conference in conjunction with the 18th International Conference on MHD Energy Conversion (ICMHD). Honolulu, Hawaii, 2011, 9 p. DOI:https://doi.org/10.2514/6.2011-3739.
9. Mishev A.L., Koldobskiy S.A., Kovaltsov G.A., et al. Updated neutron-monitor yield function: Bridging between in situ and ground-based cosmic ray measurements. J. Geophys. Res.: Space Phys. 2020, vol. 125, no. 2, e27433. DOI:https://doi.org/10.1029/2019JA027433.
10. Poluianov S., Batalla O. Cosmic-ray atmospheric cutoff energies of polar neutron monitors. Adv. Space Res. 2022, vol. 70, no. 9, pp. 2610–2617. DOI:https://doi.org/10.1016/j.asr.2022.03.037.
11. Qin R., Zhang S., Xiao J., et al. Why is Boris algorithm so good? Physics of Plasmas. 2013, vol. 20, no. 8, 084503. DOI:https://doi.org/10.1063/1.4818428.
12. Smart D.F., Shea M.A. Vertical geomagnetic cut off rigidities for epoch 2015. PoS 36th ICRC. Madison, WI, USA, 2019, 1154.
13. Tezari A., Paschalis P., Mavromichalaki H., et al. Assessing radiation exposure inside the Earth’s atmosphere.Radiation Protection Dosimetry. 2020, vol. 190, iss. 4, pp. 427–436. DOI:https://doi.org/10.1093/rpd/ncaa112.
14. Tyasto M.I., Danilova O.A., Ptitsyna N.G., Sdobnov V.E. Variations in cosmic ray cutoff rigidities during the great geomagnetic storm of November 2004. Adv. Space Res. 2013, vol. 51, no. 7, pp. 1230–1237. DOI:https://doi.org/10.1016/j.asr.2012.10.025.
15. URL: https://github.com/agmayorov/GTsimulation (accessed April 15, 2025).
16. URL: https://www.ncei.noaa.gov/products/international-geomagnetic-reference-field (accessed April 15, 2025).
17. URL: https://tools.izmiran.ru/cutoff / (accessed April 15, 2025).
18. URL: https://geomag.bgs.ac.uk/data_service/models_compass/ coord_calc.html (accessed April 15, 2025).
