Skip to main content
SpringerLink
Log in

ON THE GRADIENT OF CORONAL MAGNETIC FIELDS FROM RADIO OBSERVATIONS

  • Published:
Solar Physics Aims and scope Submit manuscript

Abstract

A technique is proposed to estimate the magnetic field and its derivative in coronal layers above solar active regions. On the basis of the theory of quasi-transverse propagation of microwaves, the measurable degree of circular polarization is related to the gradient of the coronal magnetic field. The relation is applied to the analyses of a set of microwave sunspot-associated sources at the time when they reverse the sense of their circular polarization.

Here we present the characteristic values of coronal fields H= 20 G, ∂ H/∂ l = 10-9 G cm-1 at a height of 1010 cm, estimated using spectral-polarization observations with the radiotelescope RATAN-600 (θ =18″–36″ at \(\lambda \lambda \) = 2.0–4.0 cm). The steepest gradient of 2 × 10-5 G cm-1 at h=5 × 109 cm is obtained in the case of coronal magnetic fields overlying a sunspot with a high photospheric proper motion.

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

  • Bogod, V. M., Gelfreikh, G. B., Ryabov, B. I., and Hafizov, S. R.: 1992, Transactions IAU Colloq. 141, 76.

    Google Scholar 

  • Bandiera, R.: 1982, Astron. Astrophys. 112, 52.

    Google Scholar 

  • Cohen, M. H.: 1960, Astrophys. J. 131, 664.

    Google Scholar 

  • Cohen, M. H. and Dwarkin, M. L.: 1961, J. Geophys. Res. 66, 411.

    Google Scholar 

  • Gelfreikh, G. B.: 1994, in V. Rušin, P. Heinzel, and J. C. Vial (eds.), ‘Solar Coronal Structures’, IAU Colloq. 144, 21.

  • Gelfreikh, G. B., Peterova, N. G., and Ryabov, B. I.: 1987, Solar Phys. 108, 89.

    Google Scholar 

  • Kundu, M. R. and Alissandrakis, C. E.: 1984, Solar Phys. 94, 249.

    Google Scholar 

  • Nagelis, J. and Ryabov, B. I.: 1992, Kinematika i fizika nebesnih tel 8, No. 6, 32.

    Google Scholar 

  • Peterova, N. G.: 1975, Soln. Dann. No. 3, 96.

    Google Scholar 

  • Peterova, N. G. and Akhmedov, Sh. B.: 1974, Soviet Astron. 17, 768.

    Google Scholar 

  • Peterova, N. G., Pilyeva, N. A., and Ryabov, B. I.: 1996, Baltic Astron. 5, 132.

    Google Scholar 

  • Solnechnye Dannye: 1980, No. 5.

  • Zheleznyakov, V. V.: 1970, Radio Emission of the Sun and Planets, Pergamon Press, Oxford.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Pulkovo Astronomical Observatory RAS, St.-Petersburg, Russia

    G. B. Gelfreikh

  2. Radioastrophysical Observatory, Latvian AS, Riga, Latvia

    N. A. Pilyeva & B. I. Ryabov

Authors
  1. G. B. Gelfreikh
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. N. A. Pilyeva
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. B. I. Ryabov
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gelfreikh, G.B., Pilyeva, N.A. & Ryabov, B.I. ON THE GRADIENT OF CORONAL MAGNETIC FIELDS FROM RADIO OBSERVATIONS. Solar Physics 170, 253–264 (1997). https://doi.org/10.1023/A:1004967202294

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1004967202294

Keywords

Search

Navigation