Solar Physics

, Volume 155, Issue 1, pp 171–184 | Cite as

The generation of MHD shock waves during the impulsive phase of the February 27, 1992 flare

  • Marian Karlický
  • Dušan Odstrčil


In this paper a unique 2.3–4.2 GHz radio spectrum of the flare impulsive phase, showing fast positively drifting bursts superimposed on a slowly negatively drifting burst, is presented. Analyzing this radio spectrum it was found that the flare started somewhere near the transition region, where upward propagating MHD waves were generated during the whole impulsive phase. Moreover, it was found that behind a front of these ascending MHD waves the downward propagating electron beams, which bombarded dense layers of the solar atmosphere, were accelerated. It seems that, simultaneously with the increase of beam bombardment intensity, the intensity of MHD waves was increasing and thus the MHD shock wave generation and the electron beam acceleration and bombardment formed a self-consistently amplifying flare process. At higher coronal heights this process was followed by a type II radio burst, i.e. by the MHD flare shock. To verify this concept, the numerical modeling of the shock-wave generation and propagation in space from a flare site near the transition region up to 3 solar radii was made. Comparing the thermal and magnetic field disturbances, it was found that those of magnetic origin are more relevant in this case. Combining the results of interpretation and numerical simulation, a model of the February 27, 1992 flare is suggested and new aspects of this model are discussed.


Shock Wave Flare Radio Burst Radio Spectrum Shock Wave Generation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Alfvén, H.: 1987, in A, C. Williams and T. W. Moorehead (eds.),Double Layers in Astrophysics,Google Scholar
  2. Alfvén, H. and Carlqvist, P.: 1967,Solar Phys. 1,220.Google Scholar
  3. Aurass, H, Chernov, G. P., Karlický, M., Kurths, J., and Mann, G.: 1987,Solar Phys. 112, 347.Google Scholar
  4. Benz, A.O., Magun, A., Stehling, and Su: 1992,Solar Phys. 141, 335.Google Scholar
  5. Brown, J.C., Karlický, M., MacKinnon, A. L., and van den Oord, G. H. J.: 1990,Astrophys. J. Suppl. 73, 343.Google Scholar
  6. Carlqvist, P.: 1969,Solar Phys. 7, 377.Google Scholar
  7. Chanteur, G.: 1987, in A. C. Williams and T. W. Moorehead (eds.),Double Layers in Astrophysics, NASA Conf. Publ. 2469, p.167.Google Scholar
  8. Dryer, M. and Maxwell, A: 1979,Astrophys. J. 21, 945.Google Scholar
  9. Dulk, G. A. and McLean, D. J.: 1978,Solar Phys. 57, 279.Google Scholar
  10. Fárník, F.: 1994, private communication.Google Scholar
  11. Fárník, F., Kaastra, J., Kálmán, B., Karlický, M., Slottje, C., and Valníček, B.: 1983,Solar Phys. 89, 355.Google Scholar
  12. Fu Qijun, Li Chunsheng, Gong Yuanfang, Li Wei, Zhao Bing, Shang Qiongzhen, Lu Songquan, and Hu Hanming: 1993,Solar Phys. 143, 317.Google Scholar
  13. Hildner, E., Bassi, J., Bougeret, J.L., Duncan, al.: 1989, in M. R. Kundu, B. Woodgate, and E. J. Schmahl (eds.),Energetic Phenomena on the Sun, Kluwer Academic Publishers, Dordrecht, Holland, p. 493.Google Scholar
  14. Hudson, H. S., Strong, K. T., Dennis, B. R., Zarro, D., Inda, M., Kosugi, T., and Sakao, T.: 1994,Astrophys. J. 422, L25.Google Scholar
  15. Jiřička, K., Karlický, M., Kepka, O., and Tlamicha, A.: 1993,Solar Phys. 147, 203.Google Scholar
  16. Karlický, M.: 1990,Solar Phys. 130, 347.Google Scholar
  17. Karlický, M.: 1992, in Z. Švestka, B. V. Jackson, and M. E. Machado (eds.),Eruptive Solar Flares, Springer-Verlag, Berlin, p. 171.Google Scholar
  18. Karlický, M. and Jungwirth, K.: 1989,Solar Phys. 124, 319.Google Scholar
  19. Larosa, T.N. and Moore, R. L.: 1993,Astrophys. J. 418, 912.Google Scholar
  20. MacNeice, E, McWhirter, R. W. E, Spicer, D. S., and Burgess, A.: 1984,Solar Phys. 90, 357.Google Scholar
  21. Magun, A.: 1993, private communication.Google Scholar
  22. Mann, G. and Lühr, H.: 1994,Astrophys. J. Suppl. 90, 577.Google Scholar
  23. Mariska, J. T., Emslie, A. G., and Li, P.: 1989,Astrophys.J. 341, 1067.Google Scholar
  24. Odstrčil, D.: 1994,J. Geophys. Res., in press.Google Scholar
  25. Palmer, I. D.: 1974,Solar Phys. 37, 443.Google Scholar
  26. Peratt, A. L.: 1992,Physics of the Plasma Universe, Springer-Verlag, New York.Google Scholar
  27. Pintér, S.: 1982,Space Sci. Rev. 32, 145.Google Scholar
  28. Simnett, G. M. and Haines, M. G.: 1990,Solar Phys. 130, 253.Google Scholar
  29. Singh, N., Thiemann, H., and Schunk, R.W.: 1987, in A. C. Williams and T. W. Moorehead (eds.),Double Layers in Astrophysics, NASA Conf. Publ. 2469, p. 183.Google Scholar
  30. Smart, D. F. and Shea, M. A.: 1985,J. Geophys. Res. 90, 183.Google Scholar
  31. Smart, D. F., Shea, M. A., Barron, W., and Dryer, M.: 1984, in M. A. Shea, D. F. Smart, and S. McKenna-Lawlor (eds.),STIP Symp., Maynooth, Book Crafters, Michigan, p. 139.Google Scholar
  32. Smith, D. F. and Brecht, S. H.: 1989,Astrophys. J. 344, 1004.Google Scholar
  33. Smith, D. F. and Brecht, S. H.: 1993,Astrophys. J. 406, 298.Google Scholar
  34. Spicer, D. S.: 1982,Space Sci. Rev. 31, 351.Google Scholar
  35. Vernazza, J. E., Avrett, E. H., and Loeser, R.: 1981,Astrophys. J. Suppl. 45, 635.Google Scholar
  36. Vlahos, L., Machado, M. E., Ramaty, R., Murphy, R. al.: 1989, in M. R. Kundu, B. Woodgate, and E. J. Schmahl (eds.),Energetic Phenomena on the Sun, Kluwer Academic Publishers, Dordrecht, Holland, p. 131.Google Scholar
  37. Volwerk, M. and Kuijpers, J.: 1994,Astrophys. J. Suppl. 90, 589.Google Scholar
  38. Wagner, W. J. and MacQueen, W. J.: 1983,Astron. Astrophys. 120, 136.Google Scholar
  39. Whang, Y. C.: 1987,J. Geophys. Res. 90, 4349.Google Scholar

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Marian Karlický
    • 1
  • Dušan Odstrčil
    • 1
  1. 1.Astronomical Institute of the Czech Academy of SciencesOndřejovCzech Republic

Personalised recommendations