Journal article
Cusp energetic ions : A bow shock source
Geophysical research letters, Vol.25(19), pp.3729-3732
1998
DOI: 10.1029/98GL52808
Abstract
Recent interpretations of cusp energetic ions observed by the POLAR spacecraft have suggested a new energization process in the cusp [Chen et al., 1997; 1998]. Simultaneous enhancement of H+, He+2, and O>+2 fluxes indicates that they are of solar wind origin. In the present study, we examine H+ and He+2 energy spectra from 20 eV to several 100 keV measured by the Hydra, Toroidal Imaging Mass-Angle Spectrograph (TIMAS), and Charge and Mass Magnetospheric Ion Composition Experiment (CAMMICE) on POLAR. The combined spectrum for each species is shown to be continuous with a thermal distribution below 10 keV/e and an energetic component above 20 keV/e. Energetic ions with comparable fluxes and a similar spectral shape are commonly observed downstream from the Earth's quasi-parallel (Q∥) bow shock. In addition to the similarity in the ion spectra, electric and magnetic field noise and turbulence detected in the cusp by the Plasma Wave Instrument (PWI) and Magnetic Field Experiment (MFE) onboard POLAR are similar to the previously reported observations at the bow shock. The waves appear to be coincidental to the cusp energetic ions rather than causal. We suggest that these ions are not accelerated locally in the cusp. Rather, they are accelerated at the Q∥ bow shock and enter the cusp along open magnetic field lines connecting both regions.
Details
- Title: Subtitle
- Cusp energetic ions : A bow shock source
- Creators
- S.-W Chang - University of IowaJ. D Scudder - University of IowaR Friedel - Los Alamos National LaboratoryS. A Fuselier - Lockheed MartinJ. F Fennell - The Aerospace CorporationK. J Trattner - Lockheed MartinJ. S Pickett - University of IowaH. E Spence - Boston UniversityJ. D Menietti - University of IowaW. K Peterson - Advanced Technology CenterR. P Lepping - Goddard Space Flight Center
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.25(19), pp.3729-3732
- Publisher
- American Geophysical Union
- DOI
- 10.1029/98GL52808
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Language
- English
- Date published
- 1998
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199715902771
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