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Strong and Weak Magnetic Fields: Nature of the Small-Scale Flux Elements

Published online by Cambridge University Press:  12 April 2016

Jan Olof Stenflo*
Affiliation:
Institute of Astronomy, ETH-Zentrum, CH-8092 Zurich, Switzerland

Abstract

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The 20 year old conclusion that more than 90% of the magnetic flux recorded by magnetographs in quiet and active regions is in strong-field, kG form has recently been supported by direct observations of Zeeman splitting in the infrared (near 1.6 μm). The magnetic and thermodynamic properties of the kG fluxtubes have been explored in considerable detail over the past decade, in particular through Fourier transform spectrometer observations combined with Stokes inversion procedures. The weak fields have proven to be much more elusive, and it was not until last year that the first definite identifications of intrinsically weak (less than kG) fields in the low photosphere could be made, using the Stokes V profiles of an infrared line pair.

Type
Session 4. Friendly Debate: The Relation of Quiet Sun to Active Regions
Copyright
Copyright © Astronomical Society of the Pacific 1993

References

Alfvén, H. 1967, in Magnetism and the Cosmos, eds. Hindmarsh, W.R., Lowes, F.J., Roberts, P.H., Runcorn, S.K., Oliver & Boyd, London/Edinburgh, pp. 246261.Google Scholar
Brault, J.W., Noyes, R.W. 1983, Ap. J., 269, L61.Google Scholar
Carlsson, M., Rutten, R.J., Shchukina, N.G. 1992, Astr. Ap., 253, 567.Google Scholar
Chapman, G.A., Sheeley, N.R. Jr. 1968, Solar Phys., 5, 442.Google Scholar
Faurobert-Scholl, M. 1992, Astr. Ap., in press.Google Scholar
Frazier, E.N., Stenflo, J.O. 1972, Solar Phys., 27, 330.CrossRefGoogle Scholar
Frazier, E.N., Stenflo, J.O. 1978, Astr. Ap., 70, 789.Google Scholar
Grossmann-Doerth, U., Knölker, M., Schüssler, M., Weisshaar, E. 1989, in Solar and Stellar Granulation, eds. Rutten, R.J., Severino, G., Kluwer, Dordrecht, p.481.Google Scholar
Harvey, J.W., Livingston, W. 1969, Solar Phys., 10, 283.Google Scholar
Hewagama, T., Deming, D., Jennings, D.E., Osherovich, V., Wiedemann, G., Zipoy, D., Mickey, D.L., Garcia, H. 1992, Ap. J., in press.Google Scholar
Howard, R., Stenflo, J.O. 1972, Solar Phys., 22, 402.Google Scholar
Keller, C.U. 1992, Nature, 359, 307308.Google Scholar
Keller, C.U., Solanki, S.K., Steiner, O., Stenflo, J.O. 1990, Astr. Ap., 233, 583597.Google Scholar
Livingston, W. 1991, in Solar Polarimetry, ed. November, L.J., NSO, Sunspot, NM, pp. 356360.Google Scholar
Rabin, D. 1992a, Ap. J., 390, L103L106.CrossRefGoogle Scholar
Rabin, D. 1992b, Ap. J., 391, 832844.Google Scholar
Rüedi, L. Solanki, S.K., Livingston, W., Stenflo, J.O. 1992, Astr. Ap., 263, 323338.Google Scholar
Severny, A.B. 1965, Astron. Zh., 42, 217.Google Scholar
Sheeley, N.R. Jr. 1967, Solar Phys., 1, 171.CrossRefGoogle Scholar
Solanki, S.K. 1990, in Solar Photosphere: Structure, Convection and Magnetic Fields, ed. Stenflo, J.O., IAU Symp., 138, 103120.Google Scholar
Solanki, S.K., Brigljević, V. 1992, Astr. Ap., 262, L29L32.Google Scholar
Steiner, O., Stenflo, J.O. 1990, Solar Photosphere: Structure, Convection and Magnetic Fields, ed. Stenflo, J.O., IAU Symp., 138, 181184.Google Scholar
Stenflo, J.O. 1966, Arkiv Astron., 4, 173198.Google Scholar
Stenflo, J.O. 1968, Acta Univ. Lund. II No. 2 (=Medd. Lunds Astron. Obs. Ser. II No. 153).Google Scholar
Stenflo, J.O. 1973, Solar Phys., 32, 4163.Google Scholar
Stenflo, J.O. 1989, Astron. Astrophys. Rev., 1, 348.Google Scholar
Stenflo, J.O. 1992a, in The Solar Cycle, ed. Harvey, K.L., PASP Conf. Ser., 27, 8388.Google Scholar
Stenflo, J.O. 1992b, in Proc. OSL Workshop on Electromechanical Coupling of the Solar Atmosphere, ed. Spicer, D.S., Amer. Inst. Phys., in press.Google Scholar
Stenflo, J.O., Harvey, J.W. 1985, Solar Phys., 95, 99118.Google Scholar
Stenflo, J.O., Harvey, J.W., Brault, J.W., Solanki, S.K. 1984, Astr. Ap., 131, 333346.Google Scholar
Stenflo, J.O., Solanki, S.K., Harvey, J.W. 1987, Astr. Ap., 173, 167179.Google Scholar
Zayer, I., Solanki, S.K., Stenflo, J.O. 1989, Astr. Ap., 211, 463475.Google Scholar
Zayer, I., Solanki, S.K., Stenflo, J.O., Keller, C.U. 1990, Astr. Ap., 239, 356366.Google Scholar