Toroidal ion distributions observed at high altitudes equatorward of the cusp

Citation
Mm. Huddleston et al., Toroidal ion distributions observed at high altitudes equatorward of the cusp, GEOPHYS R L, 27(4), 2000, pp. 469-472
Citations number
13
Categorie Soggetti
Earth Sciences
Journal title
GEOPHYSICAL RESEARCH LETTERS
ISSN journal
00948276 → ACNP
Volume
27
Issue
4
Year of publication
2000
Pages
469 - 472
Database
ISI
SICI code
0094-8276(20000215)27:4<469:TIDOAH>2.0.ZU;2-N
Abstract
We examine events where the TIDE and TIMAS ion instruments on board the Pol ar spacecraft have observed transversely accelerated ions (TAI) at altitude s greater than 20,000 km. We report both H+ and O+ populations that have be en heated perpendicular to the local B field but that also have a sharp low -energy cutoff to the distribution occurring at 20 - 100 eV. Analysis of an event on 21 April 1996 indicates that the formation of ion toroids may be related to solitary structures or low frequency wave pulses observed during the event. We address some of the implications of using time (as opposed t o frequency) domain techniques to analyze wave/particle energization events .