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Title: Frequency sweep rates of rising tone electromagnetic ion cyclotron waves: Comparison between nonlinear theory and Cluster observation

Abstract

Resonant pitch angle scattering by electromagnetic ion cyclotron (EMIC) waves has been suggested to account for the rapid loss of ring current ions and radiation belt electrons. For the rising tone EMIC wave (classified as triggered EMIC emission), its frequency sweep rate strongly affects the efficiency of pitch-angle scattering. Based on the Cluster observations, we analyze three typical cases of rising tone EMIC waves. Two cases locate at the nightside (22.3 and 22.6 magnetic local time (MLT)) equatorial region and one case locates at the duskside (18MLT) higher magnetic latitude (λ = –9.3°) region. For the three cases, the time-dependent wave amplitude, cold electron density, and cold ion density ratio are derived from satellite data; while the ambient magnetic field, thermal proton perpendicular temperature, and the wave spectral can be directly provided by observation. These parameters are input into the nonlinear wave growth model to simulate the time-frequency evolutions of the rising tones. The simulated results show good agreements with the observations of the rising tones, providing further support for the previous finding that the rising tone EMIC wave is excited through the nonlinear wave growth process.

Authors:
 [1]; ;  [2]; ; ;  [1]
  1. Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)
  2. Institute of Space Physics and Applied Technology, Peking University, Beijing 100871 (China)
Publication Date:
OSTI Identifier:
22403344
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 21; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPARATIVE EVALUATIONS; CYCLOTRONS; ELECTRON DENSITY; ELECTRONS; INCLINATION; ION DENSITY; IONS; NONLINEAR PROBLEMS; PROTONS; RADIATION BELTS; SCATTERING; TIME DEPENDENCE

Citation Formats

He, Zhaoguo, University of Chinese Academy of Sciences, Beijing 100049, Zong, Qiugang, Wang, Yongfu, Liu, Siqing, Lin, Ruilin, and Shi, Liqin. Frequency sweep rates of rising tone electromagnetic ion cyclotron waves: Comparison between nonlinear theory and Cluster observation. United States: N. p., 2014. Web. doi:10.1063/1.4905065.
He, Zhaoguo, University of Chinese Academy of Sciences, Beijing 100049, Zong, Qiugang, Wang, Yongfu, Liu, Siqing, Lin, Ruilin, & Shi, Liqin. Frequency sweep rates of rising tone electromagnetic ion cyclotron waves: Comparison between nonlinear theory and Cluster observation. United States. https://doi.org/10.1063/1.4905065
He, Zhaoguo, University of Chinese Academy of Sciences, Beijing 100049, Zong, Qiugang, Wang, Yongfu, Liu, Siqing, Lin, Ruilin, and Shi, Liqin. 2014. "Frequency sweep rates of rising tone electromagnetic ion cyclotron waves: Comparison between nonlinear theory and Cluster observation". United States. https://doi.org/10.1063/1.4905065.
@article{osti_22403344,
title = {Frequency sweep rates of rising tone electromagnetic ion cyclotron waves: Comparison between nonlinear theory and Cluster observation},
author = {He, Zhaoguo and University of Chinese Academy of Sciences, Beijing 100049 and Zong, Qiugang and Wang, Yongfu and Liu, Siqing and Lin, Ruilin and Shi, Liqin},
abstractNote = {Resonant pitch angle scattering by electromagnetic ion cyclotron (EMIC) waves has been suggested to account for the rapid loss of ring current ions and radiation belt electrons. For the rising tone EMIC wave (classified as triggered EMIC emission), its frequency sweep rate strongly affects the efficiency of pitch-angle scattering. Based on the Cluster observations, we analyze three typical cases of rising tone EMIC waves. Two cases locate at the nightside (22.3 and 22.6 magnetic local time (MLT)) equatorial region and one case locates at the duskside (18MLT) higher magnetic latitude (λ = –9.3°) region. For the three cases, the time-dependent wave amplitude, cold electron density, and cold ion density ratio are derived from satellite data; while the ambient magnetic field, thermal proton perpendicular temperature, and the wave spectral can be directly provided by observation. These parameters are input into the nonlinear wave growth model to simulate the time-frequency evolutions of the rising tones. The simulated results show good agreements with the observations of the rising tones, providing further support for the previous finding that the rising tone EMIC wave is excited through the nonlinear wave growth process.},
doi = {10.1063/1.4905065},
url = {https://www.osti.gov/biblio/22403344}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 12,
volume = 21,
place = {United States},
year = {Mon Dec 15 00:00:00 EST 2014},
month = {Mon Dec 15 00:00:00 EST 2014}
}