CHARACTERISTICS OF ION FLOW IN THE QUIET STATE OF THE INNER PLASMA SHEET

Academic Article

Abstract

  • We use AMPTE/IRM and ISEE 2 data to study the properties of the high beta (βi \textgreater 0.5) plasma sheet, the inner plasma sheet (IPS). Bursty bulk flows (BBFs) are excised from the two databases, and the average flow pattern in the non-BBF (quiet) IPS is constructed. At local midnight this ensemble-average flow is predominantly duskward; closer to the flanks it is mostly earthward. The flow pattern agrees qualitatively with calculations based on the Tsyganenko [1987] model (T87), where the earthward flow is due to the ensemble-average cross tail electric field and the duskward flow is the diamagnetic drift due to an inward pressure gradient. The IPS is on the average in pressure equilibrium with the lobes. Because of its large variance the average flow does not represent the instantaneous flow field. Case studies also show that the non-BBF flow is highly irregular and inherently unsteady, a reason why earthward convection can avoid a pressure balance inconsistency with the lobes. The ensemble distribution of velocities is a fundamental observable of the quiet plasma sheet flow field.
  • Authors

  • ANGELOPOULOS, V
  • KENNEL, CF
  • CORONITI, FV
  • PELLAT, R
  • Spence, Harlan
  • KIVELSON, MG
  • WALKER, RJ
  • BAUMJOHANN, W
  • FELDMAN, WC
  • GOSLING, JT
  • RUSSELL, CT
  • Status

    Publication Date

  • August 20, 1993
  • Published In

    Digital Object Identifier (doi)

    Start Page

  • 1711
  • End Page

  • 1714
  • Volume

  • 20
  • Issue

  • 16