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Torsional magnetic reconnection: The effects of localizing the non-ideal (ηJ) term

Published online by Cambridge University Press:  13 June 2011

PETER F. WYPER
Affiliation:
School of Mathematics & Statistics, University of Sheffield, Sheffield, UK ([email protected])
REKHA JAIN
Affiliation:
School of Mathematics & Statistics, University of Sheffield, Sheffield, UK ([email protected])

Abstract

Magnetic reconnection in three dimensions (3D) is a natural extension from X-point reconnection in two dimensions. Of central importance in the 3D process is a localized non-ideal region within which the plasma and magnetic field decouple allowing for field line connectivity change. In practice, localized current structures provide this localization; however, mathematically a similar effect can be achieved with the localization of plasma resistivity instead. Physically though, such approaches are unrealistic, as anomalous resistivity requires very localized currents. Therefore, we wish to know how much information is lost in localizing η instead of current? In this work we develop kinematic models for torsional spine and fan reconnection using both localized η and localized current and compare the non-ideal flows predicted by each. We find that the flow characteristics are dictated almost exclusively by the form taken for the current profile with η acting only to scale the flow. We do, however, note that the reconnection mechanism is the same in each case. Therefore, from an understanding point of view, localized η models are still important first steps into exploring the role of non-ideal effects.

Type
Papers
Copyright
Copyright © Cambridge University Press 2011

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References

[1]Pontin, D. I. and Priest, E. R. 2009 Three-dimensional null point reconnection regimes. Phys. Plasmas 16, 122101.Google Scholar
[2]Priest, E. R. and Titov, V. S. 1996 Magnetic reconnection at three-dimensional null points. Phil. Trans. R. Soc. Lon. A 354, 29512992.Google Scholar
[3]Hesse, M. and Schindler, K. 1988 A theoretical foundation of general magnetic reconnection. J. Geophys. Res. 93, 55595567.CrossRefGoogle Scholar
[4]Pontin, D. I., Bhattacharjee, A. and Galsgaard, K. 2007 Current sheet formation and non-ideal behavior at three-dimensional magnetic null points. Phys. Plasmas 14 052106.CrossRefGoogle Scholar
[5]Pontin, D. I. and Galsgaard, K. 2007 Current amplification and magnetic reconnection at a three-dimensional null point: Physical characteristics. J. Geophys. Res. 112, 3103.Google Scholar
[6]Priest, E. and Forbes, T. 2000 Magnetic Reconnection. Cambridge, UK: Cambridge University Press.CrossRefGoogle Scholar
[7]Gunnar, H. and Priest, E.Evolution of magnetic flux in an isolated reconnection process. Phys. Plasmas 10, 27122721Google Scholar
[8]Pontin, D. I., Hornig, G. and Priest, E. R. 2004 Kinematic reconnection at a magnetic null point: Spine-aligned current. Geophys. Astrophys. Fluid Dyn. 98, 407428.CrossRefGoogle Scholar
[9]Pontin, D. I., Hornig, G. and Priest, E. R. 2005 Kinematic reconnection at a magnetic null point: Fan-aligned current. Geophys. Astrophys. Fluid Dyn. 99, 7793.CrossRefGoogle Scholar
[10]Wyper, P. F. and Jain, R. 2010 Torsional magnetic reconnection at 3D null points: A phenomenological study. Phys. Plasmas. 17, 092902.CrossRefGoogle Scholar