非赤道区域激发的磁声波对辐射带电子的渡越时间散射效应

doi:10.52396/JUST-2021-0123

中国科学技术大学学报 ›› 2021, Vol. 51 ›› Issue (6): 453-458.DOI: 10.52396/JUST-2021-0123

• 研究论文:地球与空间科学 • 上一篇下一篇

非赤道区域激发的磁声波对辐射带电子的渡越时间散射效应

吴志勇^1,2, 苏振鹏^1,2*

1.中国科学技术大学地球物理与行星科学系中科院近地空间环境重点实验室,安徽合肥 230026;
2.中国科学院比较行星学卓越创新中心,安徽合肥 230026

收稿日期:2021-05-06 修回日期:2021-06-05 出版日期:2021-06-30 发布日期:2021-12-06
通讯作者: * E-mail:szpe@mail.ustc.edu.cn

Transit-time scattering of radiation belt electrons by off-equatorially generated magnetosonic waves

Wu Zhiyong^1,2, Su Zhenpeng^1,2*

1. CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026, China;
2. CAS Center for Excellence in Comparative Planetology, Hefei 230026, China

Received:2021-05-06 Revised:2021-06-05 Online:2021-06-30 Published:2021-12-06
Contact: * E-mail: szpe@mail.ustc.edu.cn

摘要/Abstract

摘要： 在内磁层中,磁声波被认为能够通过渡越时间散射影响很大能量以及投掷角范围的辐射带电子.近期观测研究发现,磁声波可以在等离子体层内的非赤道区域被激发并且在纬度覆盖范围、法向角变化等方面都与传统的赤道区域磁声波有显著不同.利用之前发展的试验粒子模型,我们研究了非赤道磁声波对辐射带电子的渡越时间散射效应.发现该效应主要发生在波列的边缘.波动纬度覆盖范围的扩展造成了该效应的有效赤道投掷角范围的收缩.相比于赤道区域磁声波, 非赤道激发的磁声波可以产生更强的能量扰动以及可忽略的投掷角扰动.

关键词: 磁声波, 辐射带, 渡越时间散射

Abstract: In the inner magnetosphere, the magnetosonic waves have been proposed to transit-time scatter the radiation belt electrons over a broad range of energy and pitch-angle. Recent observations have shown that magnetosonic waves can be generated in the off-equatorial plasmasphere, whose latitudinal coverage and propagation angle are significantly different from the traditional magnetosonic waves confined near the equator. Using our previously-developed test-particle code, we here investigate the possible transit-time scattering of radiation belt electrons by the off-equatorially generated magnetosonic waves. Our results indicate that the transit-time scattering is primarily related to the perturbation near the edge of the finite wave train. The extending of wave occurrence latitudes causes the shrinking of the equatorial pitch-angle range of the transit-time scattering. Compared to the near-equatorially confined magnetosonic waves, the off-equatorially generated magnetosonic waves produce ignorable pitch-angle perturbations but slightly stronger energy perturbations.

Key words: magnetosonic wave, radiation belt, transit-time scattering

中图分类号:

P354

吴志勇, 苏振鹏. 非赤道区域激发的磁声波对辐射带电子的渡越时间散射效应[J]. 中国科学技术大学学报, 2021, 51(6): 453-458.

WU Zhiyong, SU Zhenpeng. Transit-time scattering of radiation belt electrons by off-equatorially generated magnetosonic waves[J]. Journal of University of Science and Technology of China, 2021, 51(6): 453-458.

参考文献

[1] Russell C T, Holzer R E, Smith E J. OGO 3 observations of ELF noise in the magnetosphere. 2. The nature of the equatorial noise. J. Geophys. Res., 1970, 75: 755-768.
[2] Horne R B, Thorne R M, Glauert S A, et al. Electron acceleration in the Van Allen radiation belts by fast magnetosonic waves. Geophys. Res. Lett., 2007, 34: L17107.
[3] Shprits Y Y. Potential waves for pitch-angle scattering of near-equatorially mirroring energetic electrons due to the violation of the second adiabatic invariant. Geophys. Res. Lett., 2009, 36: L12106.
[4] Bortnik J, Thorne R M. Transit time scattering of energetic electrons due to equatorially confined magnetosonic waves. J. Geophys. Res., 2010, 115: A07213.
[5] Fu S, Ni B, Li J, et al. Interactions between magnetosonic waves and ring current protons: Gyroaveraged test particle simulations. Journal of Geophysical Research (Space Physics), 2016, 121: 8537-8553.
[6] Li J, Bortnik J, Thorne R M, et al. Ultrarelativistic electron butterfly distributions created by parallel acceleration due to magnetosonic waves. Journal of Geophysical Research (Space Physics), 2016, 121: 3212- 3222.
[7] Li J, Ni B, Ma Q, et al. Formation of energetic electron butterfly distributions by magnetosonic waves via Landau resonance. Geophys. Res. Lett., 2016, 43: 3009-3016.
[8] Yang C, Su Z, Xiao F, et al. A positive correlation between energetic electron butterfly distributions and magnetosonic waves in the radiation belt slot region. Geophys. Res. Lett., 2017, 44: 3980-3990.
[9] Ni B, Zou Z, Fu S, et al. Resonant scattering of radiation belt electrons by off-equatorial magnetosonic waves. Geophys. Res. Lett., 2018, 45: 1228-1236.
[10] Gulelmi A V, Klaine B I, Potapov A S. Excitation of magnetosonic waves with discrete spectrum in the equatorial vicinity of the plasmapause. Planet. Space Sci., 1975, 23: 279-286.
[11] Curtis S A, Wu C S. Gyroharmonic emissions induced by energetic ions in the equatorial plasmasphere. J. Geophys. Res., 1979, 84: 2597-2607.
[12] Boardsen S A, Gallagher D L, Gurnett D A, et al. Funnel-shaped, low-frequency equatorial waves. J. Geophys. Res., 1992, 97: 14967-14976.
[13] Chen L, Thorne R M, Jordanova V K, et al. Global simulation of magnetosonic wave instability in the storm time magnetosphere. J. Geophys. Res., 2010, 115: A11222.
[14] Bortnik J, Thorne R M, Ni B, et al. Analytical approximation of transit time scattering due to magnetosonic waves. Geophys. Res. Lett., 2015, 42: 1318-1325.
[15] Ma Q, Li W, Thorne R M, et al. Electron scattering by magnetosonic waves in the inner magnetosphere. Journal of Geophysical Research (Space Physics), 2016, 121: 274-285.
[16] Wu Z, Su Z, Liu N, et al. Off-equatorial source of magnetosonic waves extending above the lower hybrid resonance frequency in the inner magnetosphere. Geophysical Research Letters, 2021, 48: e2020GL091830.
[17] Su Z, Zhu H, Xiao F, et al. Latitudinal dependence of nonlinear interaction between electromagnetic ion cyclotron wave and terrestrial ring current ions. Phys. Plasmas, 2014, 21: 052310.
[18] Su Z, Zhu H, Xiao F, et al. Bounce-averaged advection and diffusion coeffificients for monochromatic electromagnetic ion cyclotron wave: Comparison between test-particle and quasi-linear models. J. Geophys. Res., 2012, 117: A09222.
[19] Zhu H, Su Z, Xiao F, et al. Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves. J. Geophys. Res., 2012, 117: A12217.
[20] Su Z, Zhu H, Xiao F, et al. Latitudinal dependence of nonlinear interaction between electromagnetic ion cyclotron wave and radiation belt relativistic electrons. J. Geophys. Res., 2013, 118: 3188-3202.
[21] Wang B, Su Z, Zhang Y, et al. Nonlinear Landau resonant scattering of near-equatorially mirroring radiation belt electrons by oblique EMIC waves. Geophys. Res. Lett., 2016, 43(8): 3628-3636.
[22] Wang G, Su Z, Zheng H, et al. Nonlinear fundamental and harmonic cyclotron resonant scattering of radiation belt ultrarelativistic electrons by oblique monochromatic EMIC waves. Journal of Geophysical Research (Space Physics), 2017, 122: 1928-1945.
[23] Inan U S, Bell T F, Helliwell R A. Nonlinear pitch angle scattering of energetic electrons by coherent VLF waves in the magnetosphere. J. Geophys. Res., 1978,83: 3235-3253.
[24] Bell T F. The nonlinear gyroresonance interaction between energetic electrons and coherent VLF waves propagating at an arbitrary angle with respect to the earth's magnetic field. J. Geophys. Res., 1984, 89: 905-918.
[25] Bortnik J, Thorne R M, Inan U S. Nonlinear interaction of energetic electrons with large amplitude chorus. Geophys. Res. Lett., 2008,35: L21102.
[26] Tao X, Bortnik J. Nonlinear interactions between relativistic radiation belt electrons and oblique whistler mode waves. Nonlinear Processes in Geophysics, 2010, 17: 599-604.
[27] Stix T H.Waves in Plasmas. New York: American Institute of Physics, 1992.
[28] Denton R E, Goldstein J, Menietti J D. Field line dependence of magnetospheric electron density. Geophys. Res. Lett., 2002,29: 2205.

非赤道区域激发的磁声波对辐射带电子的渡越时间散射效应

Transit-time scattering of radiation belt electrons by off-equatorially generated magnetosonic waves

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