Effect of nonuniform resistivity in Petschek reconnection

H Baty, E R Priest, T G Forbes

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)

Abstract

The controversial topic of the existence of a Petschek solution in steady-state magnetic reconnection for a uniform resistivity is investigated, by using two-dimensional time-dependent magnetohydrodynamic simulations. A classical localized nonuniform resistivity with a profile that is exponentially decreasing from the X point is helpful to set up the Petschek solution as a first step, using a procedure with overspecified boundary conditions. The response to changing the resistivity profile in various ways is then studied. It is found that a Petschek configuration is obtained when a quasiuniform resistivity is adopted. This is the case if the resistivity profile exhibits a weak negative gradient close to the X point, which dominates an inherent numerical contribution; otherwise an instability develops which disrupts the configuration. A truly uniform resistivity is probably only marginally stable. Finally, the validity of the arguments given by Kulsrud [Earth Planets Space 53, 417 (2001)] about the "incorrectness" of Petschek's original model is discussed. (c) 2006 American Institute of Physics.

Original languageEnglish
Article number022312
Number of pages7
JournalPhysics of Plasmas
Volume13
Issue number2
DOIs
Publication statusPublished - Feb 2006

Keywords

  • MAGNETIC RECONNECTION
  • SEPARATRIX JETS
  • MODELS

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