Extreme ionospheric ion energization and electron heating in Alfvén waves in the storm-time inner magnetosphere

TitleExtreme ionospheric ion energization and electron heating in Alfvén waves in the storm-time inner magnetosphere
Publication TypeJournal Article
Year of Publication2015
AuthorsChaston, CC, Bonnell, JW, Wygant, JR, Kletzing, CA, Reeves, GD, Gerrard, A, Lanzerotti, L, Smith, CW
JournalGeophysical Research Letters
Date Published12/2015
KeywordsAlfven waves; electron precipitation; Geomagnetic storms; ion acceleration; ion outflow; ion upflo
AbstractWe report measurements of energized outflowing/bouncing ionospheric ions and heated electrons in the inner magnetosphere during a geomagnetic storm. The ions arrive in the equatorial plane with pitch angles that increase with energy over a range from tens of eV to > 50 keV while the electrons are field-aligned up to ~1 keV. These particle distributions are observed during intervals of broadband low frequency electromagnetic field fluctuations consistent with a Doppler-shifted spectrum of kinetic Alfvén waves and kinetic field-line resonances. The fluctuations extend from L≈3 out to the apogee of the Van Allen Probes spacecraft at L≈6.5. They thereby span most of the L-shell range occupied by the ring current. These measurements suggest a model for ionospheric ion outflow and energization driven by dispersive Alfvén waves that may account for the large storm-time contribution of ionospheric ions to magnetospheric energy density.
URLhttp://doi.wiley.com/10.1002/2015GL066674http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2F2015GL066674
DOI10.1002/2015GL066674
Short TitleGeophys. Res. Lett.


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