Characteristics of ion flow in the quiet inner plasma sheet

Authors

V. Angelopoulos, University of California - Los AngelesFollow
C. F. Kennel, University of California - Los Angeles
F. V. Coroniti, University of California - Los Angeles
R. Pellat, University of California - Los Angeles
Harlan E. Spence, University of New HampshireFollow
Margaret G. Kivelson, University of California - Los AngelesFollow
Raymond J. Walker, University of California - Los AngelesFollow
W. Baumjohann, MPI far extraterrestrische Physik
W. C. Feldman, Los Alamos National Laboratory
J. T. Gosling, Los Alamos National Laboratory
C. T. Russell, University of California - Los AngelesFollow

Abstract

Abstract

We use AMPTE/IRM and ISEE 2 data to study the properties of the high beta (β_i > 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.

Department

Physics

Publication Date

8-20-1993

Journal Title

Geophysical Research Letters

Publisher

American Geophysical Union Publications

Digital Object Identifier (DOI)

10.1029/93GL00847

Document Type

Article

Recommended Citation

Angelopolous, V., C. F. Kennel, F. V. Coroniti, R. Pellat, H. E. Spence, M G. Kivelson, R. J. Walker, W. Baumjohann, W. C. Feldman, J. T. Gosling, and C. T. Russell, Characteristics of ion flow in the quiet inner plasma sheet, Geophys. Res. Lett., 20, 1711, 1993.

Rights

Copyright 1993 by the American Geophysical Union.