Kinetic Alfven waves as a source of plasma transport at the dayside magnetopause

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/94JA01095· OSTI ID:166267

Lee, L C; Johnson, J R; Ma, Z W ^[1]

---

1. Univ. of Alaska, Fairbanks, AK (United States)

As the shocked solar wind with variable plasma density and magnetic field impinges on the dayside magnetopause, it is likely to generate large-scale Alfven waves at the solar wind magnetosphere interface. However, large gradients in the density and magnetic field at the magnetopause boundary effectively couple large-scale Alfven waves with kinetic Alfven waves. In this paper the authors propose that the wave power converted into kinetic Alfven waves may play an important role in plasma transport at the dayside magnetopause and in electron acceleration along field lines. The transport can occur because, unlike the magnetohydrodynamic (MHD) shear Alfven wave, the kinetic Alfven wave has an associated parallel electric field which breaks down the {open_quotes}frozen-in{close_quotes} condition and decouples the plasma from field lines. The authors calculate the average deviation of the plasma from the field line from which they estimate the diffusion coefficient associated with these {open_quotes}bundles{close_quotes} of decoupled plasma to be approximately 10{sup 9}m{sup 2}/s. The parallel electric field also may lead to acceleration of electrons along field lines in the magnetopause boundary and may possibly provide an explanation for observed counterstreaming electron beams characterized by energies of 50-200 eV. 31 refs., 4 figs.

• OSTI ID: 166267
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A9 Vol. 99; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ALFVEN WAVES
CHARGED-PARTICLE TRANSPORT
MAGNETOPAUSE
MODE CONVERSION
SOLAR WIND