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Topology is destiny: Reconnection energetics in the corona
Earth, Planets and Space volume 53, pages571–576(2001)
Magnetic reconnection is clearly at work in the solar corona reorganizing and simplifying the magnetic field. It has also been hypothesized that this reorganization process somehow supplies the energy heating the corona. We propose a quantitative model relating the topological role (simplification) and the energetic role (heating) of magnetic reconnection. This model is used to analyze multi-wavelength observations of an X-ray bright point. In the model, motion of photospheric sources drives reconnection of coronal flux. If reconnection occurs only sporadically then energy is stored in the coronal field, and released by topological reconnection. We simulate the dynamical response of the plasma to such an energy release, and translate this into predicted observational signatures. The resulting predictions are difficult to reconcile with the observations. This suggests that while reconnection is important in the corona, energy dissipation is governed by other factors, not all of which relate to the topology of the field.
Baum, P. J. and A. Bratenahl, Flux linkages of bipolar sunspot groups: a computer study, Solar Phys., 67, 245–258, 1980.
Biskamp, D., Magnetic reconnection via current sheets, Phys. Fluids, 29, 1520–1531, 1986.
Biskamp, D., E. Schwarz, and J. F. Drake, Two-fluid theory of collisionless magnetic reconnection, Phys. Plasmas, 4, 1002–1009, 1997.
Cargill, P. J., Some implications of the nanoflare concept, ApJ, 422, 381–393, 1994.
Cargill, P. J. and J. A. Klimchuk, A nanoflare explanation for the heating of coronal loops observed by Yohkoh, ApJ, 478, 799–806, 1997.
Chapman, S. and P. C. Kendall, Liquid stability and energy transformation near a magnetic neutral line: a soluble nonlinear hydromagnetic problem, Proc. Roy. Soc., A271, 435–448, 1963.
Craig, I. J. D., Current sheet formation and dissipation in general X-point topoligies, A & A, 283, 331–338, 1994.
Craig, I. J. D. and A. N. McClymont, Linear theory of fast reconnection at an X-type neutral point, ApJ, 405, 207–215, 1993.
Dungey, J. W., Cosmic Electrodynamics, Cambridge University Press, Cambridge, U.K., 1958.
Golub, L., A. S. Krieger, J. K. Silk, A. F. Timothy, and G. S. Vaiana, Solar X-ray bright points, ApJ, 189, L93-L97, 1974.
Golub, L., A. S. Krieger, J. W. Harvey, and G. S. Vaiana, Magnetic properties of X-ray bright points, Solar Phys., 53, 111–121, 1977.
Green, R. M., Modes of annihilation and reconnection in magnetic fields, in Stellar and Solar Magnetic Fields. Proc. IAU Symp. 22, edited by R. Lust, pp. 398–404, North-Holland, 1965.
Greene, J. M., Geometrical properties of three-dimensional reconnecting magnetic fields with nulls, JGR, 93, 8583–8590, 1988.
Harvey, K. L., K. To Strong, N. Nitta, and S. Tsuneta, Are X-ray bright points the signature of magnetic field reconnection?, in Solar Active Region Evolution: Comparing Models with Observations, edited by K. S. Balasubramaniam and G. W. Simon, pp. 377–388, A.S.P., 1994.
Hassam, A. B., Reconnection of stressed magnetic fields, ApJ, 399, 159–163, 1992.
Heyn, M. and V. Semenov, Rapid reconnection in compressible plasma, Phys. Plasmas, 3, 2725–2741, 1996.
Kankelborg, C. C. and D. W. Longcope, Forward modeling of the coronal response to reconnection in an X-ray bright point, Solar Phys., 190, 59–77, 1999.
Kankelborg, C. C., A. B. C. Walker, II, R. B. Hoover, and T. W. J. Barbee, Observation and modeling of soft x-ray bright points. I. Initial results, ApJ, 466, 529–536, 1996.
Kopp, R. A. and G. Poletto, Coronal heating by nanoflares: individual events and global energetics, ApJ, 418, 496–505, 1993.
Lau, Y.-T. and J. M. Finn, Three-dimensional kinematic reconnection in the presence of field nulls and closed field lines, ApJ, 350, 672–691, 1990.
Litwin, C. and R. Rosner, On the structure of solar and stellar coronae: loops and loop heat transport, ApJ, 412, 375–385, 1993.
Longcope, D. W., Topology and current ribbons: A model for current, reconnection and flaring in a complex, evolving corona, Solar Phys., 169, 91–121, 1996.
Longcope, D. W., A model for current sheets and reconnection in X-ray bright points, ApJ, 507, 433–442, 1998.
Longcope, D. W. and S. C. Cowley, Current sheet formation along three dimensional magnetic separators, Phys. Plasmas, 3, 2885–2897, 1996.
Parker, E. N., Sweet’s mechanism for merging magnetic fields in conducting fluids, JGR, 62, 509–520, 1957.
Parker, E. N., Nanoflares and the solar x-ray corona, ApJ, 330, 474–479, 1988.
Petschek, H. E., Magnetic field annihilation, in AAS-NASA Symposium on the Physics of Solar Flares, edited by W. N. Hess, pp. 425–439, NASA, 1964.
Porter, L. J. and J. A. Klimchuk, Soft X-ray loops and coronal heating, ApJ, 454, 499–511, 1995.
Priest, E. R., C. E. Parnell, and S. F. Martin, A converging flux model on an x-ray bright point and an associated canceling magnetic feature, ApJ, 427, 459–474, 1994.
Scholer, M. and D. Roth, A simulation study on reconnection and small-scale plasmoid formation, JGR, 92, 3223–3233, 1987.
Shay, M. A., J. F. Drake, R. E. Denton, and D. Biskamp, Structure of the dissipation region during collisionless magnetic reconnection, JGR, 103, 9165, 1998.
Sonnerup, B. U. O., Magnetic field re-connexion in a highly conducting incompressible fluid, J. Plasma Phys., 4, 161–174, 1970.
Sweet, P. A., The neutral point theory of solar flares, in Electromagnetic Phenomena in Cosmical Physics, edited by B. Lehnert, pp. 123–134, Cambridge University Press, Cambridge, U.K., 1958.
Syrovatskii, S. I., Formation of current sheets in a plasma with frozen-in strong magnetic field, Sof. Phys. JETP, 33, 933–940, 1971.
Ugai, M. and T. Tsuda, Magnetic field line reconnection by localized enhancement of resistivity. I. Evolution in a compressible MHD fluid, J. Plasma Phys., 17, 337–356, 1977.
Webb, D. F., S. F. Martin, J. W. Moses, and J. W. Harvey, The correspondence between X-ray bright points and evolving magnetic features in the quiet sun, Solar Phys., 144, 15–35, 1993.
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Longcope, D.W., Kankelborg, C.C. Topology is destiny: Reconnection energetics in the corona. Earth Planet Sp 53, 571–576 (2001). https://doi.org/10.1186/BF03353272
- Current Sheet
- Magnetic Reconnection
- Minimum Energy State
- Fast Reconnection
- Photospheric Source