Whistler Mode Quasiperiodic Emissions: Contrasting Van Allen Probes and DEMETER Occurrence Rates

0538494 - ÚFA 2021 RIV US eng J - Journal Article
Němec, F. - Santolík, Ondřej - Hospodarsky, G. B. - Hájoš, Mychajlo - Demekhov, A. G. - Kurth, W. S. - Parrot, M. - Hartley, D. P.
Whistler Mode Quasiperiodic Emissions: Contrasting Van Allen Probes and DEMETER Occurrence Rates.
Journal of Geophysical Research-Space Physics. Roč. 125, č. 4 (2020), č. článku e2020JA027918. ISSN 2169-9380. E-ISSN 2169-9402
Grant - others:AV ČR(CZ) AP1401
Program: Akademická prémie - Praemium Academiae
Institutional support: RVO:68378289
Keywords : DEMETER * QP emissions * quasiperiodic emissions * RBSP
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.811, year: 2020
Method of publishing: Open access
https://hal-insu.archives-ouvertes.fr/insu-02551712/file/2020JA027918.pdf

Quasiperiodic emissions are magnetospheric whistler mode waves at frequencies between about 0.5 and 4 kHz which exhibit a nearly periodic time modulation of the wave intensity. We use large data sets of events observed by the Van Allen Probes in the equatorial region at larger radial distances and by the low-altitude DEMETER spacecraft. While Van Allen Probes observe the events at all local times and longitudes, DEMETER observations are limited nearly exclusively to the daytime and significantly less frequent at the longitudes of the South Atlantic Anomaly. Further, while the events observed by Van Allen Probes are smoothly distributed over seasons with only mild maxima in spring/autumn, DEMETER occurrence rate has a single pronounced minimum in July. The apparent inconsistency is explained by considering a nondipolar Earth's magnetic field and significant background wave intensities which in these cases prevent the quasiperiodic events from being identified in DEMETER data.
Permanent Link: http://hdl.handle.net/11104/0316290