Abstract
The small-scale structure of solar magnetic fields has been studied using simultaneous recordings in the spectral lines Fe i 5250 Å and Fe i 5233 Å, obtained with the Kitt Peak multi-channel magnetograph. We find that more than 90% of the magnetic flux in active regions (excluding the sunspots), observed with a 2.4 by 2.4″ aperture, is channelled through narrow filaments. This percentage is even higher in quiet areas. The field lines in a magnetic filament diverge rapidly with height, and part of the flux returns back to the neighbouring photosphere. Therefore the strong fields within a magnetic filament are surrounded by weak fields of the order of a few gauss of the opposite polarity. The field-strength distribution within a filament, including the surrounding opposite-polarity fields, seems to be almost the same for all filaments within a given active or quiet region.
The analysis of a scan made during an imp. 2 flare showed that observations during and after the flare would give a fictitious decrease of the magnetic energy in the region by a factor of 2–3 due to line-profile changes during the flare.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Beckers, J. M. and Schröter, E. H.: 1968, Solar Phys. 4, 142.
Chapman, G. A. and Sheeley, N. R., Jr.: 1968, Solar Phys. 5, 442.
Dunn, R. B.: 1972, Solar Phys. 22, 256.
Frazier, E. N.: 1970, Solar Phys. 14, 89.
Frazier, E. N. and Scherrer, P. H.: 1969, Solar Phys. 10, 297.
Hale, G. E. and Ellerman, F.: 1903, Publ. Yerkes Obs. 3, 1.
Harvey, J., Livingston, W., and Slaughter, C.: 1972, Proc. Conference on Line Formation in a Magnetic Field, Boulder, Colo., Sept. 1971.
Howard, R. and Stenflo, J. O.: 1972, Solar Phys. 22, 402.
Livingston, W. C.: 1968, Astrophys. J. 153, 929.
Livingston, W. and Harvey, J.: 1969, Solar Phys. 10, 294.
Livingston, W. and Harvey, J.: 1971, in R. Howard (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 51.
Sheeley, N. R., Jr.: 1967, Solar Phys. 1, 171.
Simon, G. W. and Noyes, R. W.: 1971, in R. Howard (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 663.
Stenflo, J. O.: 1968, Acta Univ. Lund II, No. 2 (Medd. Lunds Astr. Obs. II, No. 153).
Stenflo, J. O.: 1971, in R. Howard (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 101.
Stenflo, J. O. and Frazier, E. N.: 1972, Proc. Conference on Line Formation in a Magnetic Field, Boulder, Colo., Sept. 1971.
Author information
Authors and Affiliations
Additional information
Visiting Astronomer, Kitt Peak National Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation.
Rights and permissions
About this article
Cite this article
Frazier, E.N., Stenflo, J.O. On the small-scale structure of solar magnetic fields. Sol Phys 27, 330–346 (1972). https://doi.org/10.1007/BF00153105
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00153105