Skip to main content
SpringerLink
Log in

Locating Current Sheets in the Solar Corona

  • Published:
Space Science Reviews Aims and scope Submit manuscript

Abstract

Current sheets are essential for energy dissipation in the solar corona, in particular by enabling magnetic reconnection. Unfortunately, sufficiently thin current sheets cannot be resolved observationally and the theory of their formation is an unresolved issue as well. We consider two predictors of coronal current concentrations, both based on geometrical or even topological properties of a force-free coronal magnetic field. First, there are separatrices related to magnetic nulls. Through separatrices the magnetic connectivity changes discontinuously. Coronal magnetic nulls are, however, very rare. Second, inspired by the concept of generalized magnetic reconnection without nulls, quasi-separatrix layers (QSL) were suggested. Through QSL the magnetic connectivity changes continuously, though strongly. The strength of the connectivity change can be quantified by measuring the squashing of the flux tubes which connect the magnetically conjugated photospheres.

We verify the QSL and separatrix concepts by comparing the sites of magnetic nulls and enhanced squashing with the location of current concentrations in the corona. Due to the known difficulties of their direct observation, we simulated coronal current sheets by numerically calculating the response of the corona to energy input from the photosphere, heating a simultaneously observed Extreme Ultraviolet Bright Point. We did not find coronal current sheets at separatrices but at several QSL locations. The reason is that, although the geometrical properties of force-free extrapolated magnetic fields can indeed hint at possible current concentrations, a necessary condition for current sheet formation is the local energy input into the corona.

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

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Aly, J.J.: 1990, Dezso, L. (ed.), The Dynamic Sun, Proceedings of the 6th European Meeting on Solar Physics, Debrecen, Hungary, May 21–24, p. 176.

    Google Scholar 

  • Antiochos, S.K., Karpen, J.T., and DeVore, C.R.: 2002, Astrophys. J. 575, 578.

    Article  ADS  Google Scholar 

  • Aulanier, G., DeLuca, E.E., Antiochos, S.K., McMullen, R.A., and Golub, L.: 2000, Astrophys. J. 540, 1126–1142.

    Article  ADS  Google Scholar 

  • Aulanier, G., Pariat, E., and Démoulin, P.: 2005, Astron. Astrophys. 444, 961–976.

    Article  ADS  Google Scholar 

  • Axford, W.I.: 1984, Edward W. Hones, Jr. (ed.), ‘Reconnection in space and Laboratory Plasma,’ Geophysical Monograph, Vol. 30, AGU, Washington, DC, pp. 4–14.

    Google Scholar 

  • Bemporad, A., Poletto, G., Suess, S.T., Ko, Y.-K., Schwadron, N.A., Elliott, H.A., et al.: 2006, Astrophys. J. 638, 1110–1128.

    Article  ADS  Google Scholar 

  • Brown, D.S., Parnell, C.E., Deluca, E., Golub, L., and McMullen, R.A.: 2001, Solar Phys. 201, 305.

    Article  ADS  Google Scholar 

  • Büchner, J.: 2005, Danesy, A.D.G. D., Poedts, S., and Andries, J. (eds.), The Dynamic Sun: Challenges for Theory and Observations, Proceedings of the 11th European Solar Physics Meeting, Vol. ESA-SP-600, Leuven, Belgium, September 12–16.

  • Büchner, J. and Nikutowski, B.: 2005, Innes, D.E., Lagg, A. and Solanki, S.A. (eds.), Chromospheric and Coronal Magnetic Fields, Vol. ESA-SP-596, Lindau, Germany, August 30–September 2, 2005.

  • Büchner, J., Nikutowski, B., and Otto, A.: 2004a, Ireland, J. and Walsh, R. (eds.), Coronal Heating, Proceedings of the SOHO-15, Vol. ESA SP-575, St. Andrews, Scotland, September 6–9, 2004, pp. 35–50.

  • Büchner, J., Nikutowski, B., and Otto, A.: 2004b, Stepanov, A., Benevolenskaya, E. and Kosovichev, A. (eds.), Multi-Wavelength Investigations of Solar Activity, Proceedings of the IAU Symposium, Vol. 223. St. Petersburg, June 2004, pp. 353–356.

  • Büchner, J., Nikutowski, B., and Otto, A.: 2005, Gallagher, D., Horwitz, J., Perez, J., Preece, R. and Quenby, J. (eds.), Particle Acceleration in Astrophysical Plasmas: Geospace and Beyond, Vol. AGU monograph no. 156, AGU, Washington, DC, pp. 161–170.

    Google Scholar 

  • Bulanov, S.V. and Olshanetskii, M.A.: 1984, Phys. Lett. 100A, 35–38.

    ADS  Google Scholar 

  • Craig, I.J.D. and McClymont, A.N.: 1991, Astrophys. J. Lett. 371, L41–L44.

    Article  ADS  Google Scholar 

  • Démoulin, P.: 2005, Innes, D.E., Lagg, A. and Solanki, S.A. (eds.), Chromospheric and Coronal Magnetic Fields, Proceedings of the CCMAG, Vol. ESA SP-596, Lindau, Germany, August 30–September 2, 2005.

  • Démoulin, P.: 2006, J. Adv. Space Res. 37, 1269–1289.

    Article  ADS  Google Scholar 

  • Démoulin, P., Henoux, J.C., Priest, E.R., and Mandrini, C.H.: 1996a, Astron. Astrophys. 308, 643–655.

    ADS  Google Scholar 

  • Démoulin, P., Priest, E., and Lonie, D.: 1996b, J. Geophys. Res. 101(A4), 7631–7646.

    Article  ADS  Google Scholar 

  • Demoulin, P., Bagala, L.G., Mandrini, C.H., Henoux, J.C., and Rovira, M.G.: 1997, Astron. Astrophys. 325, 305–317.

    ADS  Google Scholar 

  • Giovanelli, R.: 1946, Nature (London) 158, 81.

    ADS  Google Scholar 

  • Gorbachev, V.S. and Somov, B.V.: 1988, Solar Phys. 117, 77–88.

    Article  ADS  Google Scholar 

  • Hassam, A.B.: 1992, Astrophys. J. 399(1), 159–163.

    Article  ADS  Google Scholar 

  • Hesse, M. and Schindler, K.: 1988, J. Geophys. Res. 693, 5559–5567.

    ADS  Google Scholar 

  • Lau, Y.-T. and Finn, J.M.: 1992, AIP Conference Procedings: Electromechanical Coupling of the Solar Atmosphere, Proceedings of the OSL Workshop, Vol. 267, Capri, Italy, May 27–31.

  • Lin, J., Li, T., Forbes, J., and Raymond, J.: 2005, Fleck, D.D. B., and Zurbuchen, T. (eds.), Connecting Sun and Heliosphere, Proceedings of the Solar Wind 11/SOHO 16, Whistler, Canada, June 12–17, in press.

  • Longcope, D.W.: 1998, Astrophys. J. 507, 433–442.

    Article  ADS  Google Scholar 

  • Longcope, D.W. and Cowley, S.C.: 1996, Phys. Plasmas 3(8), 2885–2897.

    Article  ADS  Google Scholar 

  • Longcope, D.W. and Klapper, I.: 2002, Astrophys. J. 579, 468–481.

    Article  ADS  Google Scholar 

  • Longcope, D., Brown, D., and Priest, E.: 2003, Phys. Plasmas 10, 3321.

    Article  ADS  Google Scholar 

  • Otto, A., Büchner, J., and Nikutowski, B.: 2006, Astron. Astrophys., (in press).

  • Parker, E.N.: 1994, Spontaneous Current Sheets in Magnetic Fields With Applications to Stellar X-rays, Oxford University Press, New York, 440 p.

    Google Scholar 

  • Parnell, C.E., Priest, E.R., and Golub, L.: 1994, Solar Phys. 151, 57–74.

    Article  ADS  Google Scholar 

  • Podladchikova, E. and Büchner, J.: 2006, Astron. Astrophys., submitted.

  • Priest, E. and Demoulin, P.: 1995.J. Geophys. Res. 100, 23.443.

    Article  ADS  Google Scholar 

  • Priest, E.R. and Forbes, T.G.: 2000, Magnetic Reconnection: MHD Theory and Applications, Cambridge University Press, New York.

    MATH  Google Scholar 

  • Priest, E.R., Parnell, C.E., and Martin, S.F.: 1994, Astrophys. J. 427, 459–474.

    Article  ADS  Google Scholar 

  • Priest, E.R., Longcope, D.W., and Heyvaerts, J.: 2005, Astrophys. J. 624, 1057–1071.

    Article  ADS  Google Scholar 

  • Schindler, K., Hesse, M., and Birn, J.: 1988, J. Geophys. Res. 93(12), 5547–5557.

    Article  ADS  Google Scholar 

  • Schrijver, C. and Title, A.: 2002, Solar Phys. 207, 223–240.

    Article  ADS  Google Scholar 

  • Solanki, S.K., Lagg, A., Woch, J., Krupp, N., and Collados, M.: 2003, Nature 425, 692.

    Article  ADS  Google Scholar 

  • Somov, B. and Titov, V.S.: 1985, Solar Phys. 102, 79–96.

    Article  ADS  Google Scholar 

  • Titov, V.S. and Priest, E.R.: 1993, Geophys. Astrophys. Fluid Dyn. 72(1–4), 249–276.

    ADS  Google Scholar 

  • Titov, V., Priest, E., and Demoulin, P.: 1993, Astron. Astrophys. 276(2), 564–570.

    ADS  Google Scholar 

  • Titov, V.S., Hornig, G., and Demoulin, P.: 2002, J. Geophys. Res. 107, SSH 3, 1.

    Google Scholar 

  • Vasyliunas, V.M.: 1975, Rev. Geophys. Space Phys. 13, 303–336.

    ADS  Google Scholar 

  • Zwingmann, W., Schindler, K., and Birn, J.: 1985, Solar Phys. 99, 133–143.

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Max-Planck-Institut für Sonnensystemforschung, Max-Planck 2, 37191, Katlenburg-Lindau, Germany

    J. Büchner

Authors
  1. J. Büchner
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to J. Büchner.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Büchner, J. Locating Current Sheets in the Solar Corona. Space Sci Rev 122, 149–160 (2006). https://doi.org/10.1007/s11214-006-8213-z

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11214-006-8213-z

Keywords

Search

Navigation