Chorus waves and spacecraft potential fluctuations: Evidence for wave-enhanced photoelectron escape

TitleChorus waves and spacecraft potential fluctuations: Evidence for wave-enhanced photoelectron escape
Publication TypeJournal Article
Year of Publication2014
AuthorsMalaspina, DM, Ergun, RE, Sturner, A, Wygant, JR, Bonnell, JW, Breneman, A, Kersten, K
JournalGeophysical Research Letters
Volume41
Issue2
Pagination236 - 243
Date Published01/2014
KeywordsVan Allen Probes
AbstractChorus waves are important for electron energization and loss in Earth's radiation belts and inner magnetosphere. Because the amplitude and spatial distribution of chorus waves can be strongly influenced by plasma density fluctuations and spacecraft floating potential can be a diagnostic of plasma density, the relationship between measured potential and chorus waves is examined using Van Allen Probes data. While measured potential and chorus wave electric fields correlate strongly, potential fluctuation properties are found not to be consistent with plasma density fluctuations on the timescales of individual chorus wave packets. Instead, potential fluctuations are consistent with enhanced photoelectron escape driven by chorus wave electric fields. Enhanced photoelectron escape may result in potential fluctuations of the spacecraft body, the electric field probes, or both, depending on the ambient plasma and magnetic field environment. These results differ significantly from prior interpretations of the correspondence between measured potential and wave electric fields.
URLhttp://doi.wiley.com/10.1002/2013GL058769
DOI10.1002/2013GL058769
Short TitleGeophys. Res. Lett.


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