Van Allen Probes Observations of Second Harmonic Poloidal Standing Alfvén Waves

Simple item page
dc.citation.firstpage611en_US
dc.citation.issueNumber1en_US
dc.citation.journalTitleJournal of Geophysical Research: Space Physicsen_US
dc.citation.lastpage637en_US
dc.citation.volumeNumber123en_US
dc.contributor.authorTakahashi, Kazueen_US
dc.contributor.authorOimatsu, Satoshien_US
dc.contributor.authorNosé, Masahitoen_US
dc.contributor.authorMin, Kyungguken_US
dc.contributor.authorClaudepierre, Seth G.en_US
dc.contributor.authorChan, Anthonyen_US
dc.contributor.authorWygant, Johnen_US
dc.contributor.authorKim, Hyominen_US
dc.date.accessioned2018-07-11T20:57:33Zen_US
dc.date.available2018-07-11T20:57:33Zen_US
dc.date.issued2018en_US
dc.description.abstractLong-lasting second-harmonic poloidal standing Alfvén waves (P2 waves) were observed by the twin Van Allen Probes (Radiation Belt Storm Probes, or RBSP) spacecraft in the noon sector of the plasmasphere, when the spacecraft were close to the magnetic equator and had a small azimuthal separation. Oscillations of proton fluxes at the wave frequency (∼10 mHz) were also observed in the energy (W) range 50–300 keV. Using the unique RBSP orbital configuration, we determined the phase delay of magnetic field perturbations between the spacecraft with a 2nπ ambiguity. We then used finite gyroradius effects seen in the proton flux oscillations to remove the ambiguity and found that the waves were propagating westward with an azimuthal wave number (m) of ∼−200. The phase of the proton flux oscillations relative to the radial component of the wave magnetic field progresses with W, crossing 0 (northward moving protons) or 180° (southward moving protons) at W ∼ 120 keV. This feature is explained by drift-bounce resonance (mωd ∼ ωb) of ∼120 keV protons with the waves, where ωd and ωb are the proton drift and bounce frequencies. At lower energies, the proton phase space density ( ) exhibits a bump-on-tail structure with occurring in the 1–10 keV energy range. This is unstable and can excite P2 waves through bounce resonance (ω ∼ ωb), where ω is the wave frequency.en_US
dc.identifier.citationTakahashi, Kazue, Oimatsu, Satoshi, Nosé, Masahito, et al.. "Van Allen Probes Observations of Second Harmonic Poloidal Standing Alfvén Waves." <i>Journal of Geophysical Research: Space Physics,</i> 123, no. 1 (2018) Wiley: 611-637. https://doi.org/10.1002/2017JA024869.en_US
dc.identifier.doihttps://doi.org/10.1002/2017JA024869en_US
dc.identifier.urihttps://hdl.handle.net/1911/102414en_US
dc.language.isoengen_US
dc.publisherWileyen_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.titleVan Allen Probes Observations of Second Harmonic Poloidal Standing Alfvén Wavesen_US
dc.typeJournal articleen_US
dc.type.dcmiTexten_US
dc.type.publicationpublisher versionen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
jgra54049.pdf
Size:
4.35 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Faculty Publications
Physics and Astronomy Publications