Energetic Electron Microinjections Observed by MMS in the Dusk Plasma Sheet and Drift Resonance Interpretation Show others and affiliations
2022 (English) In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 49, no 13, article id e2022GL098652Article in journal (Refereed) Published
Abstract [en]
Microinjection phenomena, characterized by dispersive oscillations of electron fluxes at the Pc5 period and bi-directional pitch angle anisotropy, are frequently observed by Magnetospheric Multiscale in the dusk to midnight plasma sheet. In this paper, two such events are analyzed and the features of toroidal mode drift resonance measured meanwhile are shown in detail. The prominent observation is that the fluctuations of the electron flux and the electric field have either -90 degrees or +90 degrees phase difference at the resonant energy, and the phase difference rises as the energy increases. We extend the present theory for drift resonance of toroidal mode wave with only the equatorial moving electrons in a dipole field to include bouncing electrons. The predicted phase differences based on the new theory are consistent well with the observations in the microinjection events. It is thus suggested that drift resonance may act as the forming mechanism for the observed microinjections.
Place, publisher, year, edition, pages American Geophysical Union (AGU) , 2022. Vol. 49, no 13, article id e2022GL098652
Keywords [en]
microinjection, drift resonance, toroidal mode, ULF wave
National Category
Fusion, Plasma and Space Physics
Identifiers URN: urn:nbn:se:kth:diva-315842 DOI: 10.1029/2022GL098652 ISI: 000822765000001 Scopus ID: 2-s2.0-85133919045 OAI: oai:DiVA.org:kth-315842 DiVA, id: diva2:1684124
Note QC 20220721
2022-07-212022-07-212022-07-21 Bibliographically approved