Solar Physics

, Volume 113, Issue 1–2, pp 315–318 | Cite as

Subphotospheric current systems and flares

  • Hugh S. Hudson


Subphotospheric current systems inferred from recent vector magnetograph observations (e.g. Gary et al., 1987) imply the existence of electric currents penetrating the photosphere and thus flowing deep in the solar convection zone. These currents presumably originate in an internal dynamo that supplies the observed photospheric magnetic fields through the buoyant motions of the initially deeply-buried flux tubes. The coronal fields resulting from this process therefore must carry slowly-varying currents driven by emf's remote from the surface. These currents may then drive solar-flare energy release. This paper discusses the consequences of such a deep origin of the coronal parallel currents. Simple estimates for a large active region suggest a mean current-closure depth ≥ 10,000 km, with a subphotospheric inductance ≥ 100 H and a subphotospheric stored energy ≥ 1033 ergs.


Magnetic Field Convection Flare Active Region Energy Release 


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  1. Akasofu, S.-I., 1984: Planet. Space Sci. 32, 1469.ADSCrossRefGoogle Scholar
  2. Chapman, G.A., 1981: in F.Q. Orrall (ed.), Solar Active Regions (Colorado), p. 43.Google Scholar
  3. Chapman, G.A., Herzog, A., and Lawrence, J., 1986: Nature 319, 654.ADSCrossRefGoogle Scholar
  4. Gary, G.A., Moore, R.L., Hagyard, M.J., and Haisch, B.M., 1987: Astrophys. J. 314, 782.ADSCrossRefGoogle Scholar
  5. Hirayama, T., Okamoto, T., and Hudson, H.S., 1984: in B.J. LaBonte et al.(eds.), Proc. Workshop on Solar Irradiance Variations on Active-Region Time Scales NASA CP-2310, p. 125.Google Scholar
  6. Hudson, H.S., and Willson, R.C., 1981: in L.E. Cram and J.H. Thomas (eds.), The Physics of Sunspots (NSO Sacramento Peak Observatory), p. 434.Google Scholar
  7. Kan, J.R., Akasofu, S.-I., and Lee, L.C., 1984: Solar Phys. 84, 153.ADSCrossRefGoogle Scholar
  8. Kovitya, P., and Cram, L., 1983: Solar Phys. 84, 45.ADSCrossRefGoogle Scholar
  9. Lin, R.P., and Hudson, H.S., 1976: Solar Phys. 50, 153.ADSCrossRefGoogle Scholar
  10. Lin, R.P., and Schwartz, R.A., 1987: Astrophys. J. 312, 462.ADSCrossRefGoogle Scholar
  11. Moreton, G.E., and Severny, A.B., 1968: Solar Phys. 3, 282.ADSCrossRefGoogle Scholar
  12. Spicer, D.S., Mariska, J.T., and Boris, J.P., 1986: in P.A. Sturrock et al.(eds.), Physics of the Sun (Reidel), p. 181.Google Scholar
  13. Spitzer, L., Jr., 1967: The Physics of Fully Ionized Gases (Princeton).Google Scholar
  14. Willson, R.C., Gulkis, S., Janssen, M., Hudson, H.S., and Chapman, G.A., 1981: Science 211, 700.ADSCrossRefGoogle Scholar
  15. Wilson, P.R., 1986: Solar Phys. 106, 1.ADSCrossRefGoogle Scholar

Copyright information

© D. Reidel Publishing Company 1987

Authors and Affiliations

  • Hugh S. Hudson
    • 1
  1. 1.Center for Astrophysics and Space Science University of CaliforniaSan Diego La JollaUSA

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