Journal article
Plasma Waves near the Electron Cyclotron Frequency in the Near-Sun Solar Wind
The Astrophysical journal. Supplement series, Vol.246(2), p.21
02/01/2020
DOI: 10.3847/1538-4365/ab4c3b
Abstract
Data from the first two orbits of the Sun by Parker Solar Probe reveal that the solar wind sunward of 50 solar radii is replete with plasma waves and instabilities. One of the most prominent plasma wave power enhancements in this region appears near the electron cyclotron frequency (fce). Most of this wave power is concentrated in electric field fluctuations near 0.7 fce and fce, with strong harmonics of both frequencies extending above fce. At least two distinct, often concurrent, wave modes are observed, preliminarily identified as electrostatic whistler-mode waves and electron Bernstein waves. Wave intervals range in duration from a few seconds to hours. Both the amplitudes and number of detections of these near-fce waves increase significantly with decreasing distance to the Sun, suggesting that they play an important role in the evolution of electron populations in the near-Sun solar wind. Correlations are found between the detection of these waves and properties of solar wind electron populations, including electron core drift, implying that these waves play a role in regulating the heat flux carried by solar wind electrons. Observation of these near-fce waves is found to be strongly correlated with near-radial solar wind magnetic field configurations with low levels of magnetic turbulence. A scenario for the growth of these waves is presented, which implies that regions of low-turbulence near-radial magnetic field are a prominent feature of the solar wind structure near the Sun.
Details
- Title: Subtitle
- Plasma Waves near the Electron Cyclotron Frequency in the Near-Sun Solar Wind
- Creators
- David M Malaspina - University of Colorado BoulderJasper Halekas - University of IowaLaura Berčič - University of FlorenceDavin Larson - University of California, BerkeleyPhyllis Whittlesey - University of California, BerkeleyStuart D Bale - University of California, BerkeleyJohn W Bonnell - University of California, BerkeleyThierry Dudok de Wit - Université d'OrléansRobert E Ergun - University of Colorado BoulderGregory Howes - University of IowaKeith Goetz - University of MinnesotaKatherine Goodrich - University of California, BerkeleyPeter R Harvey - University of California, BerkeleyRobert J MacDowall - Goddard Space Flight CenterMarc Pulupa - University of California, BerkeleyAnthony W Case - Center for Astrophysics Harvard & SmithsonianJustin C Kasper - University of Michigan–Ann ArborKelly E Korreck - Center for Astrophysics Harvard & SmithsonianRoberto Livi - University of California, BerkeleyMichael L Stevens - Center for Astrophysics Harvard & Smithsonian
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal. Supplement series, Vol.246(2), p.21
- Publisher
- The American Astronomical Society
- DOI
- 10.3847/1538-4365/ab4c3b
- ISSN
- 0067-0049
- eISSN
- 1538-4365
- Number of pages
- 7
- Grant note
- NNN06AA01C / NASA
- Alternative title
- Plasma Waves near the Electron Cyclotron Frequency in the Near-Sun Solar Wind
- Language
- English
- Date published
- 02/01/2020
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428793802771
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