Journal article
Ion-scale Electromagnetic Waves in the Inner Heliosphere
The Astrophysical journal. Supplement series, Vol.246(2), p.66
Early Results from Parker Solar Probe: Ushering a New Frontier in Space Exploration
02/06/2020
DOI: 10.3847/1538-4365/ab6c65
Abstract
Understanding the physical processes in the solar wind and corona that actively contribute to heating, acceleration, and dissipation is a primary objective of NASA's Parker Solar Probe (PSP) mission. Observations of circularly polarized electromagnetic waves at ion scales suggest that cyclotron resonance and wave-particle interactions are dynamically relevant in the inner heliosphere. A wavelet-based statistical study of circularly polarized events in the first perihelion encounter of PSP demonstrates that transverse electromagnetic waves at ion resonant scales are observed in 30-50% of radial field intervals. Average wave amplitudes of approximately 4 nT are measured, while the mean duration of wave events is on the order of 20 s; however, long-duration wave events can exist without interruption on hour-long timescales. Determination of wave vectors suggests propagation parallel/antiparallel to the mean magnetic field. Though ion-scale waves are preferentially observed during intervals with a radial mean magnetic field, we show that measurement constraints, associated with single spacecraft sampling of quasi-parallel waves superposed with anisotropic turbulence, render the measured coherent ion-wave spectrum unobservable when the mean magnetic field is oblique to the solar wind flow; these results imply that the occurrence of coherent ion-scale waves is not limited to a radial field configuration. The lack of radial scaling of characteristic wave amplitudes and duration suggests that the waves are generated in situ through plasma instabilities. Additionally, observations of proton distribution functions indicate that temperature anisotropy may drive the observed ion-scaley
Details
- Title: Subtitle
- Ion-scale Electromagnetic Waves in the Inner Heliosphere
- Creators
- Trevor Bowen - University of California [Berkeley]Alfred Mallet - University of California, BerkeleyJia Huang - University of MichiganKristopher KleinDavid Malaspina - University of Colorado SystemMichael Stevens - Harvard University PressStuart Bale - Imperial College LondonJ. Bonnell - University of California, BerkeleyAnthony Case - Harvard University PressBenjamin ChandranC. Chaston - University of California, BerkeleyChristopher Chen - Queen Mary University of LondonThierry Dudok de Wit - Laboratoire de Physique et Chimie de l'Environnement et de l'EspaceKeith Goetz - University of Minnesota SystemPeter Harvey - University of California, BerkeleyGregory Howes - University of IowaJ. Kasper - Harvard University PressKelly Korreck - Harvard University PressDavin Larson - University of California, BerkeleyRoberto Livi - University of California, BerkeleyRobert Macdowall - Goddard Space Flight CenterMichael Mcmanus - University of California, BerkeleyMarc Pulupa - University of California, BerkeleyJ. Verniero - University of California, BerkeleyPhyllis Whittlesey - University of California, BerkeleyPSP SWEAP Team
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal. Supplement series, Vol.246(2), p.66
- Series
- Early Results from Parker Solar Probe: Ushering a New Frontier in Space Exploration
- DOI
- 10.3847/1538-4365/ab6c65
- ISSN
- 0067-0049
- eISSN
- 1538-4365
- Publisher
- American Astronomical Society
- Language
- English
- Date published
- 02/06/2020
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428771302771
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