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Theoretical Aspects of Small-Scale Photospheric Magnetic Fields

Published online by Cambridge University Press:  08 February 2017

M. Schüssler*
Affiliation:
Universitäis-Sternwarte Geismarlandstr. 11 D-3400 Göttingen Federal Republic of Germany

Abstract

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The state of theoretical description of small-scale concentrated magnetic fields in the solar photosphere (excluding oscillations and wave propagation) is reviewed with emphasis on work done since 1982. The processes which probably lead to the formation of strong fields (flux expulsion, convective collapse) are discussed in some detail and the present understanding of the subsequent (quasi-)equilibrium state is summarized. We consider in particular the magnetic and thermal structure of the basic magnetic flux concentrations (magnetic elements) and stress the importance of radiative transfer effects, e.g. the horizontal heat exchange with the surroundings and the effect of radiation from the hot bottom and walls on the upper layers. Velocity fields within and around magnetic flux concentrations are discussed with emphasis on shift and asymmetry of the observed Stokes V-profiles which have recently been understood in terms of a downflow in the immediate vicinity outside magnetic structures. Reconnection and instabilities are considered as possible destruction processes for magnetic elements.

Type
III. Small-Scale Magnetic Fields
Copyright
Copyright © Kluwer 1990 

References

Akimov, L.A., Belkina, I.L., Dyatel, N.P.: 1982, Sov. Astron. 26, 334 Google Scholar
Akimov, L.A., Belkina, I.L., Dyatel, N.P., Marchenko, G.P.: 1987, Sov. Astron. 31, 64 Google Scholar
Anton, V.: 1989, Dissertation, Universität Göttingen Google Scholar
Auer, L.H., Heasley, J.N.: 1978, Astron. Astrophys. 64, 67 Google Scholar
Bogdan, T.J., Knölker, M: 1989, Astrophys. J. 339, 579 Google Scholar
Brandt, P., Scharmer, G.B., Ferguson, S., Shine, R.A., Tarbell, T.D., Title, A.M.: 1988, Nature 335, 238 Google Scholar
Browning, P.K., Priest, E.R.: 1983, Astrophys. J. 266, 848 Google Scholar
Chapman, G.A., Klabunde, D.P.: 1982, Astrophys. J. 261, 387 Google Scholar
Degenhardt, D.: 1989, Astron. Astrophys. , in press Google Scholar
Deinzer, W., Hensler, G., Schüssler, M., Weisshaar, E.: 1984a, Astron. Astrophys. 139, 426 Google Scholar
Deinzer, W., Hensler, G., Schüssler, M., Weisshaar, E.: 1984b, Astron. Astrophys. 139, 435 Google Scholar
Dunn, R.B., Zirker, J.B.: 1973, Solar Phys. 33, 281 Google Scholar
Ferrari, A., Massaglia, S., Kalkofen, W., Rosner, R., Bodo, G.: 1985, Astrophys. J. 298, 181 Google Scholar
Ferriz-Mas, A.: 1988, Phys. Fluids 31, 2583 Google Scholar
Ferriz-Mas, A., Moreno-Insertis, F.: 1987, Astron. Astrophys. 179, 268 Google Scholar
Ferriz Mas, A., Schüssler, M.: 1989, Geophys. Astrophys. Fluid Dyn. , in press Google Scholar
Ferriz Mas, A., Schüssler, M., Anton, V.: 1989, Astron. Astrophys. 210, 425 Google Scholar
Foukal, P., Fowler, L.: 1984, Astrophys. J. 281, 442 Google Scholar
Foukal, P., Lean, J.: 1988, Astrophys. J. 328, 347 Google Scholar
Galloway, D.J., Weiss, N.O.: 1981, Astrophys. J. 243, 945 Google Scholar
Grossmann-Doerth, U., Knölker, M., Schüssler, M., Weisshaar, E.: 1989a, in Rutten, R.J. and Severino, G. (eds.): Solar and Stellar Granulation , Kluwer, Dordrecht, p. 481 Google Scholar
Grossmann-Doerth, U., Schüssler, M., Solanki, S.K.: 1988, Astron. Astrophys. 206, L37 Google Scholar
Grossmann-Doerth, U., Schüssler, M., Solanki, S.K.: 1989b, Astron. Astrophys. , in press Google Scholar
Hasan, S.S.: 1983, see Stenflo, (1983), p. 73 Google Scholar
Hasan, S.S.: 1984, Astrophys. J. 285, 851 Google Scholar
Hasan, S.S.: 1985, Astron. Astrophys. 143, 39 Google Scholar
Hasan, S.S.: 1986, Mon. Not. Roy. Astron. Soc. 219, 357 Google Scholar
Hasan, S.S.: 1988, Astrophys. J. 332, 499 Google Scholar
Hasan, S.S.: 1989, preprint Google Scholar
Hasan, S.S., Kneer, F.: 1986, Astron. Astrophys. 158, 288 Google Scholar
Hasan, S.S., Schüssler, M.: 1985, Astron. Astrophys. 151, 69 Google Scholar
Herbold, G., Ulmschneider, P., Spruit, H.C., Rosner, R.: 1985, Astron. Astrophys. 145, 157 Google Scholar
Hirayama, T., Hamana, S., Mizugaki, K.: 1985, Solar Phys. 99, 43 Google Scholar
Hollweg, J.V.: 1982, Astrophys. J. 257, 345 Google Scholar
Howard, R.W., Stenflo, J.O.: 1972, Solar Phys. 22, 402 Google Scholar
Hurlburt, N.E., Toomre, J.: 1988, Astrophys. J. 327, 920 Google Scholar
Hurlburt, N.E., Toomre, J., Massaguer, J.M.: 1984, Astrophys. J. 282, 557 Google Scholar
Illing, R.M.E., Landman, D.A., Mickey, D.L.: 1975, Astron. Astrophys. 41, 183 Google Scholar
Kalkofen, W., Bodo, G., Massaglia, S., Rossi, P.: 1989, in Rutten, R.J. and Severino, G. (eds.): Solar and Stellar Granulation , Kluwer, Dordrecht, p. 571 Google Scholar
Kalkofen, W., Rosner, R., Ferrari, A., Massaglia, S.: 1986, Astrophys. J. 304, 519 Google Scholar
Kemp, J.C., Macek, J.H., Nehring, F.W.: 1984, Astrophys. J. 278, 863 CrossRefGoogle Scholar
Knölker, M., Schüssler, M.: 1988, Astron. Astrophys. 202, 275 Google Scholar
Knölker, M., Schüssler, M., Weisshaar, E.: 1988, Astron. Astrophys. 194, 257 Google Scholar
Landi Degl'Innocenti, E.: 1985, in Schmidt, H.U. (ed.): Theoretical Problems in High Resolution Solar Physics , MPA 212, Max-Planck Institut für Astrophysik, München, p. 162 Google Scholar
Lawrence, J.K., Chapman, G.A.: 1988, Astrophys. J. 335, 996 Google Scholar
Livi, S.H.B., Wang, J., Martin, S.F.: 1985, Australian J. Phys. 38, 855 Google Scholar
Martin, S.F., Livi, S.H.B., Wang, J.: 1985, Australian J. Phys. 38, 929 Google Scholar
Massaglia, S., Bodo, G., Kalkofen, W., Rosner, R.: 1988, Astrophys. J. 333, 925 Google Scholar
Massaglia, S., Bodo, G., Rossi, P.: 1989, Astron. Astrophys. 209, 399 Google Scholar
Mehltretter, J.P.: 1974, Solar Phys. 38, 43 Google Scholar
Meyer, F.: 1976, in Bonnet, R.-M., Delache, Ph. (eds.): The Energy Balance and Hydrodynamics of the Solar Chromosphere and Corona , IAU-Colloq. No. 36, Nice, p. 111 Google Scholar
Meyer, F., Schmidt, H.U., Simon, G.W., Weiss, N.O.: 1979, Astron. Astrophys. 76, 35 Google Scholar
Meyer, F., Schmidt, H.U., Weiss, N.O.: 1977, Mon. Not. Roy. Astron. Soc. 179, 741 Google Scholar
Montesinos, B., Thomas, J.H.: 1989, Astrophys. J. 337, 977 Google Scholar
Muller, R.: 1975, Solar Phys. 45, 105 Google Scholar
Muller, R.: 1983, Solar Phys. 85, 113 Google Scholar
Muller, R., Roudier, Th.: 1984, Solar Phys. 94, 33 Google Scholar
Muller, R., Roudier, Th., Hulot, J.C.: 1989, Solar Phys. 119, 229 Google Scholar
Nordlund, Å.: 1983, see Stenflo (1983), p. 79 Google Scholar
Nordlund, Å.: 1984, in Guyenne, T.D. and Hunt, J.J. (eds.): The Hydromagnetics of the Sun , ESA SP-220, p. 37 Google Scholar
Nordlund, Å.: 1985a, in Schmidt, H.U. (ed.): Theoretical Problems in High Resolution Solar Physics , MPA 212, Max-Planck Institut für Astrophysik, München, p. 1 Google Scholar
Nordlund, Å.: 1985b, in Schmidt, H.U. (ed.): Theoretical Problems in High Resolution Solar Physics , MPA 212, Max-Planck Institut für Astrophysik, München, p. 101 Google Scholar
Nordlund, Å.: 1986, in Deinzer, W. et al. (eds.): Small Scale Magnetic Flux Concentrations in the Solar Photophere , Abh. Akad. d. Wiss. Göttingen No. 38, Vandenhoeck & Ruprecht, Göttingen, p. 83 Google Scholar
Osherovich, V., Flå, T., Chapman, G.A.: 1983, Astrophys. J. 268, 412 Google Scholar
Pantellini, F.G.E., Solanki, S.K., Stenflo, J.O.: 1988, Astron. Astrophys. 189, 263 Google Scholar
Parker, E.N.: 1963, Astrophys. J. 138, 552 Google Scholar
Parker, E.N.: 1975, Solar Phys. 40, 291 Google Scholar
Parker, E.N.: 1978, Astrophys. J. 221, 368 Google Scholar
Parker, E.N.: 1979, Cosmical Magnetic Fields , Clarendon, Oxford Google Scholar
Parker, E.N.: 1984, Astrophys. J. 283, 343 Google Scholar
Pizzo, V.J.: 1986, Astrophys. J. 302, 785 Google Scholar
Pneuman, G.W., Solanki, S.K., Stenflo, J.O.: 1986, Astron. Astrophys. 154, 231 Google Scholar
Priest, E.R.: 1982, Solar Magneto-Hydrodynamics , Reidel, Dordrecht Google Scholar
Proctor, M.R.E., Weiss, N.O.: 1982, Rep. Progr. Phys. 45, 1317 Google Scholar
Ribes, E., Rees, D.E., Fang, C.: 1985, Astrophys. J. 296, 268 Google Scholar
Roberts, B.: 1976, Astrophys. J. 204, 268 Google Scholar
Roberts, B., Webb, A.R.: 1978, Solar Phys. 56, 5 Google Scholar
Rogerson, J.B.: 1961, Astrophys. J. 134, 331 Google Scholar
Sanchez-Almeida, J., Collados, J., del Toro Iniesta, J.: 1988, Astron. Astrophys. 201, L37 Google Scholar
Schatten, K.H., Mayr, H.G., Omidvar, K., Maier, E.: 1986, Astrophys. J. 311, 460 Google Scholar
Schmidt, H.U., Simon, G.W., Weiss, N.O.: 1985, Astron. Astrophys. 148, 191 Google Scholar
Schmidt, H.U., Wegmann, R.: 1983, in Brosowski, B. and Martensen, E. (eds.): Dynamical Problems in Mathematical Physics , Lang, Frankfurt/Main, p. 137 Google Scholar
Schüssler, M.: 1979, Astron. Astrophys. 71, 79 Google Scholar
Schüssler, M.: 1984a, in Guyenne, T.D. and Hunt, J.J. (eds.): The Hydromagnetics of the Sun , ESA SP-220, p. 67 Google Scholar
Schüssler, M.: 1984b, Astron. Astrophys. 140, 453 Google Scholar
Schüssler, M.: 1986, in Deinzer, W. et al. (eds.): Small Scale Magnetic Flux Concentrations in the Solar Photophere , Abh. Akad. d. Wiss. Göttingen No. 38, Vandenhoeck & Ruprecht, Göttingen, p. 103 Google Scholar
Schüssler, M.: 1987a, in Schröter, E.-H. et al. (eds.): The Role of Fine-Scale Magnetic Fields on the Structure of the Solar Atmosphere , Cambridge University Press, p. 223 Google Scholar
Schüssler, M.: 1987b, in Durney, B.R. and Sofia, S. (eds.): The Internal Solar Angular Velocity , Reidel, Dordrecht, p. 303 Google Scholar
Schüssler, M., Solanki, S.K.: 1988, Astron. Astrophys. 192, 338 Google Scholar
Simon, G.W., Weiss, N.O., Nye, A.: 1983, Solar Phys. 87, 65 Google Scholar
Solanki, S.K.: 1986, Astron. Astrophys. 168, 311 Google Scholar
Solanki, S.K.: 1989, Astron. Astrophys. , in press Google Scholar
Solanki, S.K., Pahlke, K.-D.: 1988, Astron. Astrophys. 201, 143 Google Scholar
Solanki, S.K., Stenflo, J.O.: 1984, Astron. Astrophys. 140, 185 Google Scholar
Solanki, S.K., Stenflo, J.O.: 1986, Astron. Astrophys. 170, 120 Google Scholar
Solov'ev, A.A.: 1984, Sov. Astron. , 28, 54 Google Scholar
Spruit, H.C.: 1976, Solar Phys. 50, 269 Google Scholar
Spruit, H.C.: 1977, Solar Phys. 55, 3 CrossRefGoogle Scholar
Spruit, H.C.: 1979, Solar Phys. 61, 363 Google Scholar
Spruit, H.C.: 1982, Astron. Astrophys. 108, 348 Google Scholar
Spruit, H.C.: 1983, see Stenflo, (1983), p. 41 Google Scholar
Spruit, H.C., Roberts, B.: 1983, Nature 304, 401 Google Scholar
Spruit, H.C., Schüssler, M., Solanki, S.K.: 1989, in Cox, A.N. and Livingston, W.C. (eds.): The Solar Interior and Atmosphere , University of Arizona Press, Tucson, in press Google Scholar
Spruit, H.C., van Ballegooijen, A.A., Title, A.M.: 1987, Solar Phys. 110, 115 Google Scholar
Spruit, H.C., Zweibel, E.G.: 1979, Solar Phys. 62, 15 Google Scholar
Steffen, M., Ludwig, H.-G., Krüß, A.: 1989, Astron. Astrophys. 213, 371 Google Scholar
Steiner, O., Pizzo, V.J.: 1989, Astron. Astrophys. 211, 447 Google Scholar
Steiner, O., Pneuman, G.W., Stenflo, J.O.: 1986, Astron. Astrophys. 170, 126 Google Scholar
Stenflo, J.O. (ed.): 1983, Solar and Stellar Magnetic Fields: Origins and Coronal Effects , IAU-Symp. No. 102, Reidel, Dordrecht Google Scholar
Stenflo, J.O.: 1987, Solar Phys. 114, 1 Google Scholar
Stenflo, J.O.: 1989, Astron. Astrophys. Rev. 1, 3 Google Scholar
Stenflo, J.O., Harvey, J.W.: 1985, Solar Phys. 95, 99 Google Scholar
Stenflo, J.O., Solanki, S.K., Harvey, J.W.: 1987, Astron. Astrophys. 171, 305 Google Scholar
Sterling, A.C., Hollweg, J.V.: 1988, Astrophys. J. 327, 950 Google Scholar
Suematsu, Y., Shibata, K., Nishikawa, T., Kitai, R.: 1982, Solar Phys. 75, 99 Google Scholar
Thomas, J.H.: 1985, in Schmidt, H.U. (ed.): Theoretical Problems in High Resolution Solar Physics , MPA 212, Max-Planck Institut für Astrophysik, München, p. 126 Google Scholar
Thomas, J.H.: 1988, Astrophys. J. 337, 407 Google Scholar
Title, A.M., Tarbell, T.D., Topka, K.P.: 1987, Astrophys. J. 317, 892 Google Scholar
Title, A.M., Tarbell, T.D., Topka, K.P., Cauffman, D., Balke, C., Scharmer, G.: 1989, preprint Google Scholar
Tsinganos, K.C.: 1980, Astrophys. J. 239, 746 Google Scholar
Unno, W., Ando, H.: 1979, Geophys. Astrophys. Fluid Dyn. 12, 107 Google Scholar
Unno, W., Ribes, E.: 1979, Astron. Astrophys. 73, 314 Google Scholar
Van Ballegooijen, A.A.: 1985, discussion remark in Schmidt, H.U. (ed.): Theoretical Problems in High Resolution Solar Physics , MPA 212, Max-Planck Institut für Astrophysik, München, p. 177 Google Scholar
Venkatakrishnan, P.: 1983, J. Astrophys. Astron. 4, 135 Google Scholar
Venkatakrishnan, P.: 1985, J. Astrophys. Astron. 6, 21 Google Scholar
Venkatakrishnan, P.: 1986, Nature 322, 156 Google Scholar
Webb, A.R., Roberts, B.: 1978, Solar Phys. 59, 249 Google Scholar
Weiss, N.O.: 1966, Proc. Roy. Soc. A293, 310 Google Scholar
Weiss, N.O.: 1977, in Müller, E.A. (ed.), Highlights of Astronomy 4, 241 Google Scholar
Weiss, N.O.: 1981a, J. Fluid Mech. 108, 247 CrossRefGoogle Scholar
Weiss, N.O.: 1981b, J. Fluid Mech. 108, 273 Google Scholar
Wiehr, E.: 1985, Astron. Astrophys. 149, 217 Google Scholar
Wilson, P.R.: 1977, Astrophys. J. 214, 611 Google Scholar
Zayer, I., Solanki, S.K., Stenflo, J.O.: 1989, Astron. Astrophys. 211, 463 Google Scholar
Zwaan, C.: 1978, Solar Phys. 60, 213 Google Scholar