Observations Directly Linking Relativistic Electron Microbursts to Whistler Mode Chorus: Van Allen Probes and FIREBIRD II

0487743 - ÚFA 2018 RIV US eng J - Journal Article
Breneman, A. W. - Crew, A. - Sample, J. - Klumpar, D. - Johnson, A. - Agapitov, O. - Shumko, M. - Turner, D. L. - Santolík, Ondřej - Wygant, J. R. - Cattell, C. A. - Thaller, S. A. - Blake, B. - Spence, H. - Kletzing, C. A.
Observations Directly Linking Relativistic Electron Microbursts to Whistler Mode Chorus: Van Allen Probes and FIREBIRD II.
Geophysical Research Letters. Roč. 44, č. 22 (2017), s. 11265-11272. ISSN 0094-8276. E-ISSN 1944-8007
R&D Projects: GA ČR GA17-07027S
Grant - others:AV ČR(CZ) AP1401
Program: Akademická prémie - Praemium Academiae
Institutional support: RVO:68378289
Keywords : VLF-CHORUS * RADIATION BELT * ZONE ELECTRONS * SOURCE REGION * AURORAL-ZONE * GEM STORMS * PRECIPITATION * ASSOCIATION * RESOLUTION * EMISSIONS
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 4.339, year: 2017
http://onlinelibrary.wiley.com/doi/10.1002/2017GL075001/epdf

We present observations that provide the strongest evidence yet that discrete whistler mode chorus packets cause relativistic electron microbursts. On 20 January 2016 near 1944 UT the low Earth orbiting CubeSat Focused Investigations of Relativistic Electron Bursts: Intensity, Range, and Dynamics (FIREBIRD II) observed energetic microbursts (near L = 5.6 and MLT = 10.5) from its lower limit of 220 keV, to 1 MeV. In the outer radiation belt and magnetically conjugate, Van Allen Probe A observed rising-tone, lower band chorus waves with durations and cadences similar to the microbursts. No other waves were observed. This is the first time that chorus and microbursts have been simultaneously observed with a separation smaller than a chorus packet. A majority of the microbursts do not have the energy dispersion expected for trapped electrons bouncing between mirror points. This confirms that the electrons are rapidly (nonlinearly) scattered into the loss cone by a coherent interaction with the large amplitude (up to similar to 900 pT) chorus. Comparison of observed time-averaged microburst flux and estimated total electron drift shell content at L = 5.6 indicate that microbursts may represent a significant source of energetic electron loss in the outer radiation belt.
Permanent Link: http://hdl.handle.net/11104/0282379