Comparative Study of Dayside Pulsating Auroras Induced by Ultralow-Frequency WavesShow others and affiliations
2023 (English)In: Universe, E-ISSN 2218-1997, Vol. 9, no 6, article id 258Article in journal (Refereed) Published
Abstract [en]
Pulsating auroras are usually observed with ultralow-frequency (ULF) waves in the Pc 3-5 band (period 10-600 s). These auroras are thought to result from interactions between energetic electrons and chorus waves, but their relationship with ULF waves remains an open question. In this study, we investigated this question by conducting a comparative study on two ULF wave events with pulsating auroras observed near the magnetic footprints. Conjugate observations from the Magnetospheric Multiscale mission and the Chinese Yellow River Station were used. In both events, lower-band chorus waves were observed, which were suggested to be connected with the auroral pulsations by wavelet analysis. The intensity of these waves oscillates at the period of the ULF waves, but the physics laid behind them differs by events. During the event of 22 January 2019, compressional ULF waves changed the threshold for the whistler anisotropy instability periodically, affecting the emission of chorus waves. In the event on 10 January 2016, poloidal ULF waves modulated the chorus wave generation by regulating electron temperature anisotropy through drift resonance. ULF waves in these events may originate from perturbations in the solar wind. We highlight the role of ULF waves in the solar wind-magnetosphere-ionosphere coupling, which requires further study.
Place, publisher, year, edition, pages
MDPI AG , 2023. Vol. 9, no 6, article id 258
Keywords [en]
ultralow-frequency wave, chorus wave, pulsating aurora, dayside aurora, wave-particle interaction, drift resonance, dayside magnetosphere, outer magnetosphere
National Category
Fusion, Plasma and Space Physics
Identifiers
URN: urn:nbn:se:kth:diva-331836DOI: 10.3390/universe9060258ISI: 001015792800001Scopus ID: 2-s2.0-85163753323OAI: oai:DiVA.org:kth-331836DiVA, id: diva2:1782586
Note
QC 20230714
2023-07-142023-07-142024-08-28Bibliographically approved