Japan Geoscience Union Meeting 2024

Presentation information

[J] Poster

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM17] Space Plasma Science

Thu. May 30, 2024 5:15 PM - 6:45 PM Poster Hall (Exhibition Hall 6, Makuhari Messe)

convener:Takanobu Amano(Department of Earth and Planetary Science, University of Tokyo), Yohei Miyake(Graduate School of System Informatics, Kobe University), Shogo Isayama(Interdisciplinary Graduate School of Engineering Sciences, Kyushu University), Takayuki Umeda(Information Initiative Center, Hokkaido University)

5:15 PM - 6:45 PM

[PEM17-P09] Harmonic structure of upper hybrid waves driven by energetic electrons and associated electron cyclotron harmonic waves

*Tsubasa Kotani1, Mieko Toida2, Toseo Moritaka2, Satoshi Taguchi1 (1.Kyoto University, 2.National Institute for Fusion Science)

Keywords:harmonic structure of upper hybrid waves, electron cyclotron harmonic waves, particle-in-cell simulation

Recent simulation studies have investigated the non-linear development of lower hybrid wave instabilities driven by ring-like energetic ions [1,2,3]. It has been found that the harmonic structure of lower hybrid waves can be generated by energetic ions through non-linear wave-wave coupling [2,3]. This generation process follows the resonant condition (k1±k2 = k3 and ω1±ω2 = ω3), leading to excited wave modes exhibiting the wavenumbers and frequencies that are integer multiples of those of lower hybrid waves.

In this meeting, we study the non-linear development of upper hybrid wave instabilities driven by ring-like energetic electrons, by one-dimensional, electromagnetic, particle-in-cell simulations. We show that the harmonic structure of upper hybrid waves (hereafter harmonic UHWs) can be generated by energetic electrons through non-linear wave-wave coupling, just as with the lower hybrid waves and energetic ions. After the excitation of harmonic UHWs, electron cyclotron waves (ECWs) can be excited below ωUH where ωUH is the upper hybrid resonance frequency. We find that ECWs can also be excited above ωUH by non-linear wave-wave coupling between UHWs and ECWs. Our findings suggest a new possible generation mechanism of electron cyclotron harmonic waves.

References

[1] T. Kotani, M. Toida, T. Moritaka, and S. Taguchi (2021), PIC Simulation of Energetic-ion Injection Effects on Nonlinear Development of Lower Hybrid Wave Instabilities, Journal of the Physical Society of Japan, 90, 124501, https://journals.jps.jp/doi/10.7566/JPSJ.90.124501.

[2] T. Kotani, M. Toida, T. Moritaka, and S. Taguchi (2023), Harmonic Structure of Lower Hybrid Waves Driven by Energetic Ions at 4000 km Altitude: PIC Simulation, Geophysical Research Letters, 50, e2022GL102356. https://doi.org/10.1029/2022GL102356.

[3] T. Kotani, M. Toida, T. Moritaka, and S. Taguchi (2023), Simulation study of the harmonic structure of lower hybrid waves driven by energetic ions, Physical Review E, 108, 035208, https://link.aps.org/doi/10.1103/PhysRevE.108.035208.