Abstract
This paper presents an integrated analysis of GOES 6, 7 and neutron monitor observations of solar cosmic-ray event following the 1990 May 24 solar flare. We have used a model which includes particle injection at the Sun and at the interplanetary shock front and particle propagation through the interplanetary medium. The model does not attempt to simulate the physical processes of coronal transport and shock acceleration, therefore the injections at the Sun and at the shock are represented by source functions in the particle transport equation. By fitting anisotropy and angle-average intensity profiles of high-energy (>30 MeV) protons as derived from the model to the ones observed by neutron monitors and at GOES 6 and 7, we have determined the parameters of particle transport, the injection rate and spectrum at the source. We have made a direct fit of uncorrected GOES data with both primary and secondary proton channels taken into account.
The 1990 May 24–26 energetic proton event had a double-peaked temporal structure at energies ∼ 100 MeV. The Moreton (shock) wave nearby the ‘flare core’ was seen clearly before the first injection of accelerated particles into the interplanetary medium. Some (correlated with this shock) acceleration mechanism which operates in the solar corona at a height up to one solar radius is regarded as a source of the first (prompt) increase in GOES and neutron monitor counting rates. The proton injection spectrum during this increase is found to be hard (spectral index γ ≈ 1.6) at lower energies (∼ 30 MeV) with a rapid steepening above 300 MeV. Large values of the mean free path (λ ≈ 1.8 AU for 1 GV protons in the vicinity of the Earth) led to a high anisotropy of arriving protons. The second (delayed) proton increase was presumably produced by acceleration/injection of particles by an interplanetary shock wave at height of ≈ 10 solar radii. Our analysis of the 1990 May 24–26 event is in favour of the general idea that a number of components of energetic particles may be produced while the flare process develops towards larger spatial/temporal scales.
Similar content being viewed by others
References
Beeck, J., Mason, G. M., Hamilton, D. C., Wibberenz, G., Kunow, H., Hovestadt, D., and Klecker, B.: 1987, Astrophys. J. 322, 1052.
Beeck, J., Mason, G. M., Marsden, R. G., Hamilton, D. C., and Sunderson, T. R.: 1990, J. Geophys. Res. 95, 10279.
Bieber, J. W., Evenson, P. A., and Pomerantz, M. A.: 1986, J. Geophys. Res. 91, 8713.
Bieber, J. W., Matthaeus, W. H., Smith, C. W., Wanner, W., Kallenrode, M.-B., and Wibberenz, G.: 1994, Astrophys. J. 420, 294.
Borovkov, L. P., Lazutin, L. L., Shumilov, O. I., and Vashenyuk, E. V.: 1987, Proc. 20 Int. Cosmic Ray Conf., Moscow 3, 124.
Bulanov, S. V., Sasorov, P. V., and Syrovatskii, S. I.: 1979, Proc. XI Leningrad Seminar on Space Phys. Ioffe Phys.-Tech. Inst. Publ., p. 83.
Bykov, A. M. and Fleishman, G. D.: 1992, Monthly Notices Roy. Astron. Soc. 255, 269.
Bykov, A. M. and Toptyghin, I. N.: 1993, Uspekhi Phys. Nauk 163, 19.
Cane, H. V.: 1985, J. Geophys. Res. 90, 191.
Cane, H. V., Reames, D. V., and von Rosenvinge, T. T.: 1988, J. Geophys. Res. 93, 9555.
CD GOES: 1992, Space Environment Monitor 1-Minute and 5-Minute Averages, January 1986–June 1992, Version 1, National Geophys. Data Center, 325 Broadway, Boulder, CO, U.S.A.
Debrunner, H.: 1994, ‘High Energy Solar Phenomena’, AIP Conf. Proc. 294, 207.
Debrunner, H., Lockwood, J. A., and Ryan, J. M.: 1993, Astrophys. J. 409, 822.
Domingo, V., Hynds, R. J., and Stevens, G. A.: 1979, Proc. 16th Int. Cosmic Ray Conf. 5, 192.
Earl, J. A.: 1981, Astrophys J. 251, 739.
Gueglenko, V. G., Kocharov, G. E., Kovaltsov, G. A., Kocharov, L. G., and Mandzhavidze, N. Z.: 1990, Solar Phys. 125, 91.
Heras, A. M., Sanahuja, B., Smith, Z. K., Detman, T., and Dryer, M.: 1991, Proc. 22nd Int. Cosmic Ray Conf., Dublin 3, 284.
Heras, A. M., Sanahuja, B., Smith, Z. K., Detman, T., and Dryer, M.: 1992, Astrophys. J. 391, 359.
Heras, A. M., Sanahuja, B., Sanderson, T. R., Marsden, R. G., and Wenzel, K.-P.: 1994, J. Geophys. Res. 99, 43.
Kahler, S. W.: 1993, J. Geophys. Res. 98, 5607.
Kahler, S. W.: 1994, Astrophys. J. 428, 837.
Kallenrode, M.-B.: 1993, J. Geophys. Res. 98, 19037.
Kallenrode, M.-B., Cliver, E. W., and Wibberenz, G.: 1992, Astrophys. J. 391, 370.
Kananen, H., Tanskanen, P. J., Gentile, L. C., Shea, M. A., and Smart, D. F.: 1991, Proc. 22nd Int. Cosmic Ray Conf., Dublin 3, 145.
Kocharov, L. G. and Kocharov, G. E.: 1984, Space Sci. Rev. 38, 89.
Kocharov, L. G., Lee, J. W., Zirin, H., Kovaltsov, G. A., Usoskin, I. G., Pyle, K. R., Shea, M. A., and Smart, D. F.: 1994, Solar Phys. 155, 149.
Kunstmann, J. E.: 1979, Astrophys. J. 229, 812.
Miroshnichenko, L. I., Perez-Peraza, J., Alvarez-M. M., Sorokin, O. M., Vashenyuk, E. V., and Gallegos, S. A.: 1990, Proc. 21st Int. Cosmic Ray Conf., Adelaida 5, 5.
Ng, C. K. and Reames, D. V.: 1994, Astrophys. J. 424, 1032.
Parker, E. N.: 1963, Interplanetary Dynamical Processes, Interscience, New York.
Reames, D. V., Cane, H. V., and von Rosenvinge, T. T.: 1990, Astrophys. J. 357, 259.
Reid, G. C.: 1964, J. Geophys. Res. 69, 2659.
Richardson, I. G. and Cane, H. V.: 1993, J. Geophys. Res. 98, 15295.
Ruffolo, D.: 1995, Astrophys. J. 442, 861.
Sarris, E. T., Anagnostopoulos, G. C., and Trochoutsos, P. C.: 1984, Solar Phys. 93, 195.
Shea, M. A.:1994, private communication.
Shea, M. A. and Smart, D. F.: 1982, Space Sci. Rev. 32, 251.
Švestka, Z. and Fritzová-Švestková, L.: 1974, Solar Phys. 36, 417.
Toptyghin, I. N.: 1983, Cosmic Rays in Interplanetary Magnetic Fields, Nauka, Moscow.
Torsti, J. and Schultz, C. G.: 1992, ‘Proc. 1st SOHO Workshop, Annapolis, Maryland, U.S.A.’, ESA SP-348, 343.
Torsti, J., Vainio, R., Halen, S., and Kuusela, J.: 1994, ‘Proc. Third SOHO Workshop, Estes Park, Colorado, U.S.A.’, ESA SP-373, 311.
Vashenyuk, E. V., Miroshnichenko, L. I., Sorokin, M. O., Perez-Peraza, J., and Gallegos-Krus, A.:1993, Geomagn. i Aeronomia 33, No. 5, 1.
Wenzel, K.-P., Reinhard, R., and Sanderson, T. R.: 1981, Adv. Space Res. 1(3), 105.
Wibberenz, G., Lanzerotti, L. J., and Venkatesan, D.: 1976, J. Geophys. Res. 81, 5807.
Wibberenz, G., Kecskemety, K., Kunow, H., Somogyi, A., Iwers, B., Logachev, Yu. I., and Stolpovskii, V. G.: 1989, Solar Phys. 124, 353.
Zwickl, R. D.: 1992, ‘GOES Energetic Particle Correction Algorithm”, in CD GOES Space Environment Monitor 1-Minute and 5-Minute Averages, January 1986–June 1992, Version 1, National Geophys. Data Center, 325 Broadway, Boulder, CO, U.S.A.
Author information
Authors and Affiliations
Additional information
Visiting Associate from St. Petersburg State Technical University, St. Petersburg 195251, Russia.
Rights and permissions
About this article
Cite this article
Torsti, J., Kocharov, L.G., Vainio, R. et al. The 1990 May 24 solar cosmic-ray event. Sol Phys 166, 135–158 (1996). https://doi.org/10.1007/BF00179359
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00179359