Shocklets, SLAMS, and field-aligned ion beams in the terrestrial foreshock
Abstract
We present Wind spacecraft observations of ion distributions showing field-aligned beams (FABs) and large-amplitude magnetic fluctuations composed of a series of shocklets and short large-amplitude magnetic structures (SLAMS). We show that the SLAMS are acting like a local quasi-perpendicular shock reflecting ions to produce the FABs. Previous FAB observations reported the source as the quasi-perpendicular bow shock. The SLAMS exhibit a foot-like magnetic enhancement with a leading magnetosonic whistler train, consistent with previous observations. The FABs are found to have T_b ~ 80-850 eV, V_b/V_sw ~ 1-2, T_{b,perp}/T{b,para} ~ 1-10, and n_b/n_i ~ 0.2-14%. Strong ion and electron heating are observed within the series of shocklets and SLAMS increasing by factors \geq 5 and \geq 3, respectively. Both the core and halo electron components show strong perpendicular heating inside the feature.
Keywords
Cite
@article{arxiv.1207.5561,
title = {Shocklets, SLAMS, and field-aligned ion beams in the terrestrial foreshock},
author = {L. B. Wilson and A. Koval and D. G. Sibeck and A. Szabo and C. A. Cattell and J. C. Kasper and B. A. Maruca and M. Pulupa and C. S. Salem and M. Wilber},
journal= {arXiv preprint arXiv:1207.5561},
year = {2015}
}
Comments
11 pages, 3 EPS figures, submitted to Geophysical Research Letters