Abstract
X-ray and EUV observations of the solar corona reveal a very complex and dynamic environment where there are many examples of structures that are believed to outline the Sun's magnetic field. In this present study, the authors investigate the temporal response of the temperature, density and pressure of a solar coronal plasma contained within a magnetic loop to an intermittent heating source generated by Ohmic dissipation. The energy input is produced by a one-dimensional MHD flare model. This model is able to reproduce some of the statistical properties derived from X-ray flare observations. In particular the heat deposition consists of both a sub-flaring background and much larger, singular dissipative events. Two different heating profiles are investigated: (a) the spatial average of the square of the current along the loop and (b) the maximum of the square of the current along the loop. For case (a), the plasma parameters appear to respond more to the global variations in the heat deposition about its average value rather than to each specific event. For case (b), the plasma quantities are more intermittent in their evolution. In both cases the density response is the least bursty signal. It is found that the time-dependent energy input can maintain the plasma at typical coronal temperatures. Implications of these results upon the latest coronal observations are discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bak, P., Tang, C., and Wiesenfeld, K.: 1987, Phys. Rev. Lett. 59, 381.
Berghmans, D. and Clette, F.: 1999, Solar Phys. 186, 207.
Boffetta, G., Carbone, V., Giuliani, P., Veltri, P., and Vulpiani, A.: 1999 Phys. Rev. Lett. 83, 4662.
Braginskii, S. I.: 1965, Rev. Plasma Phys. 1, 205.
Chupp, E. L.: 1990, Astrophys. J. 73, 213.
Cook, J. W., Cheng, C.-C., Jacobs, V. L., and Antiochos, S. K.: 1989, Astrophys. J. 338, 1176.
Crosby, N. B.: 1996, PhD Thesis, Université de Paris VII, France.
Crosby, N. B., Aschwanden, M. J. and Dennis, B. R.: 1993, Solar Phys. 143, 275.
Dmitruk, P., Gómez, D. O., and DeLuca, E. E.: 1998, Astrophys. J. 505, 974.
Einaudi, G., Velli, M., Politano, H., and Pouquet, A.: 1996, Astrophys. J. 457, L113.
Frisch, U., Pouquet, A., Sulem, P. L., and Meneguzzi, M.: 1983, J. Mécanique Théor. Appl. 20, 191.
Galsgaard, K. and Nordlund, A.: 1996, J. Geophys. Res. 101, 13445.
Galtier, S.: 1999, Astrophys. J. 521, 483.
Galtier, S.: 2000, Solar Phys., submitted.
Galtier, S. and Pouquet, A.: 1998, Solar Phys. 179, 141.
Galtier, S. and Walsh, R. W.: 2000, Solar Phys., in preparation.
Georgoulis, M. K. and Vlahos, L.: 1998, Astron. Astrophys. 336, 721.
Georgoulis, M. K., Velli, M., and Einaudi, G.: 1998, Astrophys. J. 497, 957.
Hudson, H.: 1991, Solar Phys. 133, 357.
Hwa, T. and Kardar, M.: 1992, Phys. Rev. A45, 7002.
Kadanoff, L. P., Nagel, S. R., Wu, L., and Zhou, S.: 1989, Phys. Rev. A39, 6524.
Klimchuk, J. A., Lemen, J. R., Feldman, U., Tsuneta, S., and Uchida, Y.: 1992, Publ. Astron. Soc. Japan 44, L181.
Krucker, S. and Benz, A. O.: 1998, Astrophys. J. 501, L213.
Lu, E. T. and Hamilton, R. J.: 1991, Astrophys. J. 380, L89.
Mariska, J. T.: 1987, Astrophys. J. 319, 465.
Mercier, C. and Trottet, G.: 1997, Astrophys. J. 474, L65.
Parker, E. N.: 1988, Astrophys. J. 330, 474.
Parker, E. N.: 1994, Spontaneous Current Sheets in Magnetic Fields, International Series on Astronomy and Astrophysics, Oxford University Press, Oxford.
Pearce, G., Rowe, A. K., and Yeung, J.: 1993, Astrophys. Space Sci. 208, 99.
Priest, E. R.: 1982, Solar Magnetohydrodynamics, D. Reidel Publ. Co., Dordrecht, Holland.
Priest, E. R., Foley, C. R., Heyvaerts, J., Arber, T. D., Culhane, J. L., and Acton, L. W: 1998, Nature 393, 545.
Schrijver, C. J. et al.: 1999, Solar Phys. 187, 261.
Spitzer, L.: 1962, Physics of Fully Ionized Gases, Interscience, New York.
Vlahos, L., Georgoulis, M., Kluiving, R., and Paschos, P.: 1995, Astron. Astrophys. 299, 897.
Walsh, R. W.: 1999, Proceedings of 8th SOHO Workshop, SP-446, 81.
Walsh, R. W., Bell, G. E., and Hood, A. W.: 1995, Solar Phys. 161, 83.
Walsh, R. W., Bell, G. E., and Hood, A. W.: 1996, Solar Phys. 169, 33.
Walsh, R. W., Bell, G. E., and Hood, A. W.: 1997, Solar Phys. 171, 81.
Walsh, R. W., Ireland, J., Harrison, R. A., and Priest, E. R.: 1997, ESA SP404, 717.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Walsh, R., Galtier, S. Intermittent heating in a model of solar coronal loops. Solar Physics 197, 57–73 (2000). https://doi.org/10.1023/A:1026520614533
Issue Date:
DOI: https://doi.org/10.1023/A:1026520614533