Physics – Plasma Physics
Scientific paper
Dec 2004
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004jgra..10912220e&link_type=abstract
Journal of Geophysical Research, Volume 109, Issue A12, CiteID A12220
Physics
Plasma Physics
30
Space Plasma Physics: Charged Particle Motion And Acceleration, Space Plasma Physics: Nonlinear Phenomena, Magnetospheric Physics: Auroral Phenomena (2407), Magnetospheric Physics: Electric Fields (2411), Magnetospheric Physics: Energetic Particles, Precipitating
Scientific paper
Satellite observations have established that parallel electric fields of both upward and downward current regions of the aurora are supported, at least in part, by strong double layers. The purpose of this article is to examine the role of double layers in auroral electron acceleration using direct measurements of parallel electric fields and the accompanying particle distributions, electrostatic waves, and nonlinear structures; the concentration is on the upward current region. Direct observations of the ionospheric boundary of the auroral cavity suggest that a stationary, oblique double layer carries a substantial, albeit a minority fraction (~10% to ~50%) of the auroral potential. An order of magnitude density gradient results in an asymmetric electric field signature. Oblique double layers with amplitudes greater than 100 mV/m have been verified in ~3% and may occur in up to 11% of auroral cavity crossings, so it is feasible that strong double layers are a principal acceleration mechanism. In this article we also present a second type of double layer that has a symmetric electric field signature and is seen inside of the auroral cavity. These structures are a possible signature of a midcavity or high-altitude acceleration mechanism. Numerical solutions of the Vlasov-Poisson equations support the possibility of midcavity double layers and indicate that trapped electrons can play an important role in the double-layer structure.
Andersson L.-L.
Carlson Carl W.
Ergun Robert E.
Goldman Martin V.
Hull Arthur J.
No associations
LandOfFree
Auroral particle acceleration by strong double layers: The upward current region does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Auroral particle acceleration by strong double layers: The upward current region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Auroral particle acceleration by strong double layers: The upward current region will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1085839