Quasiperiodic Emissions: Fine Structure Corresponding to a Bouncing Wave

0581778 - ÚFA 2025 RIV US eng J - Journal Article
Němec, F. - Santolík, Ondřej - Hospodarsky, G. - Kurth, W. S.
Quasiperiodic Emissions: Fine Structure Corresponding to a Bouncing Wave.
Geophysical Research Letters. Roč. 51, č. 2 (2024), č. článku e2023GL106459. ISSN 0094-8276. E-ISSN 1944-8007
Institutional support: RVO:68378289
Keywords : elf-vlf emissions * van allen probes * magnetic pulsations * conjugate observations * cluster * satellite * propagation * modulation * spacecraft * quasiperiodic emissions * QP emissions * Van Allen Probes
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 5.2, year: 2022
Method of publishing: Open access
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL106459

Quasiperiodic (QP) emissions are whistler-mode electromagnetic waves observed in the Earth's inner magnetosphere whose intensity has a nearly periodic time modulation with typical modulation periods on the order of minutes. Some events exhibit, on top of the main modulation period, an additional fine inner modulation with modulation periods on the order of seconds. We use high-resolution multi-component electromagnetic wave data obtained by the Van Allen Probes spacecraft to investigate one such event. Detailed wave analysis demonstrates that the fine inner modulation is due to a wave packet bouncing back and forth between the hemispheres. The presence of a density duct is important for the formation of the event, as demonstrated by the increased ratio of wave power propagating away from the equator (a tentative source region) within the duct. The main QP modulation period corresponds to the plasma number density modulation observed just outside the plasmasphere.
Permanent Link: https://hdl.handle.net/11104/0350421