Walsh, AP;
Owen, CJ;
Fazakerley, AN;
Forsyth, C;
Dandouras, I;
(2011)
Average magnetotail electron and proton pitch angle distributions from Cluster PEACE and CIS observations.
Geophysical Research Letters
, 38
, Article L06103. 10.1029/2011GL046770.
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Abstract
We present results from the first systematic survey of proton and electron pitch angle distributions in the magnetotail, based on Cluster CIS and PEACE data binned by proton plasma beta (beta(p)). The proton distributions conform to the canonical picture of magnetotail ions - a boundary layer made up of Earthward streaming and bidirectional field-aligned particles, consistent with recent observations of time-varying beamlets, which gives way to a broadly isotropic central plasma sheet when beta(p) similar to 3. The electron distributions are significantly different from the canonical picture. A "boundary layer" made up of bidirectional field-aligned electrons is observed to values of beta(p) as high as 17. This boundary quickly gives way to perpendicular-dominated electrons close to the neutral sheet. Hence, our results suggest that, on average, there is no extended, isotropic electron plasma sheet and that the proton plasma sheet is not routinely encountered until higher beta(p) than commonly assumed. Citation: Walsh, A. P., C. J. Owen, A. N. Fazakerley, C. Forsyth, and I. Dandouras (2011), Average magnetotail electron and proton pitch angle distributions from Cluster PEACE and CIS observations, Geophys. Res. Lett., 38, L06103, doi:10.1029/2011GL046770.
Type: | Article |
---|---|
Title: | Average magnetotail electron and proton pitch angle distributions from Cluster PEACE and CIS observations |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1029/2011GL046770 |
Publisher version: | http://dx.doi.org/10.1029/2011GL046770 |
Language: | English |
Additional information: | Copyright 2011 by the American Geophysical Union |
Keywords: | Sheet boundary-layer, Central plasma sheet, Field, Scattering, Tail |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
URI: | https://discovery.ucl.ac.uk/id/eprint/1301800 |
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