Skip to Main content Skip to Navigation
Conference papers

Multi-spacecraft observations of quasiperiodic emissions

Abstract : Whistler mode electromagnetic waves observed in the inner magnetosphere at frequencies of a few kilohertz sometimes exhibit a nearly periodic modulation of the wave intensity. The modulation periods may range from several tens of seconds up to a few minutes, and such emissions are usually called quasiperiodic (QP) emissions. The origin of these events is still unclear, but it seems that their generation might be related to compressional ULF magnetic field pulsations which periodically modulate resonance conditions in the source region. From an observational point of view, single-point measurements are quite insufficient, as they do not allow us to distinguish between spatial and temporal variations of the emissions. Multipoint observations of these events are, on the other hand, rather rare. We present several QP wave events observed simultaneously by several different spacecraft (Cluster, Van Allen Probes, THEMIS, DEMETER). We demonstrate that although the quasiperiodic modulation is observed over a huge spatial region, individual spacecraft do not see the QP elements at exactly the same times. Moreover, when an event is observed simultaneously on the dawnside and on the duskside, the modulation period observed on the duskside is about twice larger than the modulation period observed on the dawnside. We present a qualitative explanation of these phenomena.
Document type :
Conference papers
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03573540
Contributor : Nathalie POTHIER Connect in order to contact the contributor
Submitted on : Tuesday, February 15, 2022 - 12:35:33 PM
Last modification on : Tuesday, May 10, 2022 - 3:24:58 PM
Long-term archiving on: : Monday, May 16, 2022 - 7:47:04 PM

File

EGU2016-2629-1.pdf
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

Frantisek Nemec, Jolene S. Pickett, George Hospodarsky, Ondrej Santolik, Barbora Bezdekova, et al.. Multi-spacecraft observations of quasiperiodic emissions. EGU General Assembly 2016, Apr 2016, Vienne, Austria. ⟨insu-03573540⟩

Share

Metrics

Record views

16

Files downloads

0