Articles | Volume 11, issue 2
Nonlin. Processes Geophys., 11, 259–266, 2004
https://doi.org/10.5194/npg-11-259-2004

Special issue: International Workshops on Nonlinear Waves and Chaos in Space...

Nonlin. Processes Geophys., 11, 259–266, 2004
https://doi.org/10.5194/npg-11-259-2004

  14 Apr 2004

14 Apr 2004

Theory and observation of double discontinuities

Y. C. Whang Y. C. Whang
  • Catholic University of America, Room 107, Pangborn Hall, Washington, D. C. 20064, USA

Abstract. Recent research using high-resolution magnetic field data to examine the interior structures of MHD shocks in interplanetary space and in the magnetotail led to a surprising discovery that a slow-mode shock is often followed by an adjoining rotational discontinuity layer on the postshock side. The thickness of each layer is of the order of a few ion inertial lengths. Such a compound structure is known as a double discontinuity. When the magnetic field rotates by several degrees per ion inertial length inside a thin layer, the Hall current term becomes important in the generalized Ohm's law. Steady state solutions based on the Hall-MHD theory have been obtained to show the merging of a rotational layer and a slow shock layer to form a compound structure like the observed double discontinuities.