Global Simulation of Electron Cyclotron Harmonic Wave Instability in a Storm-Time Magnetosphere

Journal Article · 26 February 2020 · Geophysical Research Letters

DOI: https://doi.org/10.1029/2019GL086368 · OSTI ID:1604012

Liu, Xu  ^[1]; Chen, Lunjin  ^[1]; Engel, Miles A.  ^[2]; Jordanova, Vania Koleva  ^[2]

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1. Univ. of Texas at Dallas, Richardson, TX (United States)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Electron cyclotron harmonic (ECH) waves are electrostatic emissions between the ECHs and play a dominant role for precipitating energetic electrons in the magnetotail. Statistically, the ECH wave intensity is stronger at nightside and dawnside than at dayside and duskside. In this study, we, for the first time, simulate the global ECH wave evolution during a geomagnetic storm event using Ring current Atmosphere interactions Model with Self-Consistent Magnetic field (RAM-SCB) combined with a linear growth rate solver.We find that the simulation results are generally consistent with the statistical and real-time observations. The ECH wave instability is much stronger at nightside and dawnside, compared to the instability at dayside and duskside. Before a geomagnetic storm (quiet time), the unstable regions of the ECH waves lie beyond $$5R_E$$ with a weak instability level. During the main phase of a geomagnetic storm, the unstable regions can extend to a lower altitude $$(3R_E)$$ with a strong instability level. Finally, during the recovery phase, the unstable regions return to $$5$$ ~ $$6R_E$$. We also find that the inner boundary of unstable ECH wave regions is coincident with the plasmapause location during the whole geomagnetic storm event.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: National Aeronautics and Space Administration (NASA); USDOE Laboratory Directed Research and Development (LDRD) Program; National Science Foundation (NSF); USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: 89233218CNA000001; 80NSSC18K1112; NNX17AI52G; AGS-1702805
• OSTI ID: 1604012
• Report Number(s): LA-UR-19-31985; TRN: US2104176
• Journal Information: Geophysical Research Letters, Vol. 47, Issue 6; ISSN 0094-8276
• Publisher: American Geophysical UnionCopyright Statement
• Country of Publication: United States
• Language: English