Van Allen Probes Observations of Chorus Wave Vector Orientations: Implications for the Chorus-to-Hiss Mechanism

0503880 - ÚFA 2020 RIV US eng J - Journal Article
Hartley, D. P. - Kletzing, C. A. - Chen, L. - Horne, R. B. - Santolík, Ondřej
Van Allen Probes Observations of Chorus Wave Vector Orientations: Implications for the Chorus-to-Hiss Mechanism.
Geophysical Research Letters. Roč. 46, č. 5 (2019), s. 2337-2346. ISSN 0094-8276. E-ISSN 1944-8007
R&D Projects: GA ČR(CZ) GA17-07027S
Grant - others:AV ČR(CZ) AP1401
Program: Akademická prémie - Praemium Academiae
Institutional support: RVO:68378289
Keywords : Van Allen Probes * EMFISIS * chorus waves * plasmaspheric hiss * plasmaspheric plumes * wave normal angle
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 4.497, year: 2019
Method of publishing: Open access
http://nora.nerc.ac.uk/id/eprint/522337/7/Hartley_et_al-2019-Geophysical_Research_Letters.pdf

Using observations from the Van Allen Probes EMFISIS instrument, coupled with ray tracing simulations, we determine the fraction of chorus wave power with the conditions required to access the plasmasphere and evolve into plasmaspheric hiss. It is found that only an extremely small fraction of chorus occurs with the required wave vector orientation, carrying only a small fraction of the total chorus wave power. The exception is on the edge of plasmaspheric plumes, where strong azimuthal density gradients are present. In these cases, up to 94% of chorus wave power exists with the conditions required to access the plasmasphere. As such, we conclude that strong azimuthal density gradients are actually a requirement if a significant fraction of chorus wave power is to enter the plasmasphere and be a source of plasmaspheric hiss. This result suggests it is unlikely that chorus directly contributes a significant fraction of plasmaspheric hiss wave power.

Permanent Link: http://hdl.handle.net/11104/0295659