Academic Article


  • We discuss the implications of results arising from an analysis of a Petschek‐type reconnection model for the interpretation of data obtained at the terrestrial magnetopause. In this model, reconnection is initiated through the introduction of a reconnection electric field in the diffusion region. The magnitude of the electric field is considered to be small compared to the product of characteristic values of the magnetic field strength and Alfvén speed in the system; that is, we study the case of weak reconnection only. Outside the diffusion region, the behavior of the plasma is governed by the ideal MHD equations. Petschek's original analysis is generalized through the introduction of a spatially and temporally varying reconnection rate, that is, the reconnection line has a finite length and the reconnection electric field along it varies in time. Additionally, the magnetic fields on either side of the current sheet (although uniform initially) may have arbitrary strength and are skewed relative to each other. New features are that (1) the plasma velocity may have a shear across the current layer, and (2) the densities on either side of the current sheet may be different in general. The reconnection electric field initiates a localized disruption of the current sheet, and the associated disturbances are propagated into the system by MHD waves. With this model we are able to explain and interpret various features observed at the terrestrial magnetopause, such as accelerated plasma flows and flux transfer events. We describe magnetic field signatures predicted by our model. We also show that reconnection is capable of generating surface waves. A property of our model is that it predicts a displacement of the magnetopause when time‐dependent reconnection is occurring.
  • Authors

  • HEYN, MF
  • Farrugia, Charles
  • Status

    Publication Date

  • November 1, 1995
  • Published In

    Digital Object Identifier (doi)

    Start Page

  • 21779
  • End Page

  • 21789
  • Volume

  • 100
  • Issue

  • A11