Abstract
When globally mapping the observed photospheric magnetic field into the corona, the interaction of the solar wind and magnetic field has been treated either by imposing source surface boundary conditions that tacitly require volume currents outside the source surface (Schatten, Wilcox, and Ness, 1969) or by limiting the interaction to thin current sheets between oppositely directed field regions (Wolfson, 1985). Yet observations and numerical MHD calculations suggest the presence of non-force-free volume currents throughout the corona as well as thin current sheets in the neighborhoods of the interfaces between closed and open field lines or between oppositely directed open field lines surrounding coronal helmet-streamer structures. This work presents a model including both horizontal volume currents and streamer sheet currents. The present model builds on the magnetostatic equilibria developed by Bogdan and Low (1986) and the current-sheet modeling technique developed by Schatten (1971). The calculation uses synoptic charts of the line-of-sight component of the photospheric magnetic field measured at the Wilcox Solar Observatory. Comparison of an MHD model with the calculated model results for the case of a dipole field and comparison of eclipse observations with calculations for CR 1647 (near solar minimum) show that this horizontal current-current-sheet model reproduces polar plumes and axes of corona streamers better than the source-surface model and reproduces coronal helmet structures better than the current-sheet model.
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References
Altschuler, M. D. and Newkirk, G.: 1969,Solar Phys. 9, 131.
Bagenal, F. and Gibson, S.: 1991,J. Geophys. Res. 96, 17663.
Bogdan, T. J. and Low, B. C.: 1986,Astrophys. J. 306, 271.
Hoeksema, J. T., Wilcox, J. M., and Scherrer, P. H.: 1982,J. Geophys. Res. 87, 10331.
Levine, R. H., Altschuler, M. D., Harvey, J. W., and Jackson, B. V.: 1977,Astrophys. J. 215, 636.
Loucif, M. L. and Craag, A.: 1988, in R. C. Altrock (ed.),Solar and Stellar Coronal Structure and Dynamics, Sunspot, New Mexico, p. 406.
Low, B. C.: 1985,Astrophys. J. 293, 31.
Newkirk, G.: 1972, in C. P. Sonett, P. J. Coleman, Jr., and J. M. Wilcox (eds.),The Solar Wind Two, Scientific and Technical Information Office, NASA, Washington D.C., p. 11.
Pneuman, G. W. and Kopp, R. A.: 1971,Solar Phys. 18, 258.
Schatten, K. H.: 1971,Cosmic Electrodynamics 2, 232.
Schatten, K. H., Wilcox, J. W., and Ness, N. F.: 1969,Solar Phys. 9, 442.
Steinolfsen, R. S., Suess, S. T., and Wu, S. T.: 1982,Astrophys. J. 255, 730.
Wang, Y. M. and Sheeley, N. R., Jr.: 1990,Astrophys. J. 355, 726.
Wang, Y. M. and Sheeley, N. R., Jr.: 1992,Astrophys. J. 392, 310.
Wolfson, R.: 1985,Astrophys. J. 288, 769.
Zhao, X. P. and Hoeksema, J. T.: 1992, inCoronal Streamers, Coronal Loops, and Solar Wind Composition, ESA Publications Division, p. 117.
Zhao, X. P. and Hoeksema, J. T.: 1993a,Solar Phys. 143, 41.
Zhao, X. P. and Hoeksema, J. T.: 1993b, inThe Proceedings of the Second SOHO Workshop, in press.
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Zhao, X., Hoeksema, J.T. A coronal magnetic field model with horizontal volume and sheet currents. Sol Phys 151, 91–105 (1994). https://doi.org/10.1007/BF00654084
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DOI: https://doi.org/10.1007/BF00654084