Charged particle behavior in the growth and damping stages of ultralow frequency waves: Theory and Van Allen Probes observations

Xu, Zhou; Wang, Zi Han; Zong, Q.; Rankin, R.; Kivelson, M. G.; Chen, Xing Ran; Blake, J. B.; Wygant, J. R.; Kletzing, C.

doi:10.1002/2016ja022447

Cited by 59 publications

(125 citation statements)

References 47 publications

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“…Zong et al, 2007). More recently, the conventional picture of drift resonance has been extended to account for the finite temporal and spatial extents of the ULF waves (Zhou et al, 2015;Zhou et al, 2016;Li et al, 2017;Hao et al, 2017), with the predicted signatures (such as increasingly tilted stripes in particle energy spectrum and boomerang-shaped structures in pitch angle spectrum) consistent with observations. Such diagnostic signatures have been unambiguously identified in Van Allen Probes observations (Dai et al, 2013;Claudepierre et al, 2013;Hao et al, 2014;Foster et al, 2015;Chen et al, 2016), providing clear evidence on the presence of drift resonance in the inner magnetosphere.…”

Section: Introductionmentioning

confidence: 64%

“…We next follow Zhou et al (2016) to fix the ratio, by assuming a simplistic PSD distribution (a spatially independent power law distribution, ∝ W −3 ) for background particles, so as to convert W to . We next follow Zhou et al (2016) to fix the ratio, by assuming a simplistic PSD distribution (a spatially independent power law distribution, ∝ W −3 ) for background particles, so as to convert W to .…”

Section: Comparison With Observationsmentioning

confidence: 99%

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Drift‐Bounce Resonance Between Charged Particles and Ultralow Frequency Waves: Theory and Observations

Zhu

Zhou

et al. 2020

JGR Space Physics

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Ultralow frequency (ULF) waves have long been known to resonate with magnetospheric charged particles through their drift and bounce motions. Most research interest has focused on the resonance with drift motion, which can accelerate charged particles at very high energies. The role of the bounce motion, especially for particles with lower energies, has attracted less attention so far. Here we start from the general theory of wave-particle interactions to predict the characteristic, observable signatures of drift-bounce resonance. Such signatures can be described in the particle pitch angle spectrum as a series of inclined stripes, with the inclination angle depending on the latitude of the observing spacecraft. Each stripe is also twisted at two conjugated pitch angles, suggesting significant phase shifts across resonant pitch angles. These predicted signatures are found consistent with observations from the THEMIS (Time History of Events and Macroscale Interactions during Substorms) spacecraft, and therefore provide an identification of drift-bounce resonance together with a validated picture over the importance of particle's bounce motion in the ULF wave-particle interactions.

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Section: Introductionmentioning

confidence: 64%

Section: Comparison With Observationsmentioning

confidence: 99%

Drift‐Bounce Resonance Between Charged Particles and Ultralow Frequency Waves: Theory and Observations

Zhu

Zhou

et al. 2020

JGR Space Physics

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“…An increasing number of spacecraft observations suggest that ULF waves significantly affect the dynamics of charged particles in the inner magnetosphere (e.g., Dai et al, ; Foster et al, ; Pokhotelov et al, ; Ren et al, , ; Volwerk, ; Yang, Zong, Fu, Li, et al, ; Zhou et al, , ; Zong et al, , ). In terms of particle energy and species, the inner magnetosphere can be divided into the radiation belts, ring current, and plasmasphere.…”

Section: Introductionmentioning

confidence: 99%

Low‐Energy (<200 eV) Electron Acceleration by ULF Waves in the Plasmaspheric Boundary Layer: Van Allen Probes Observation

et al. 2017

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We report observational evidence of cold plasmaspheric electron (<200 eV) acceleration by ultralow frequency (ULF) waves in the plasmaspheric boundary layer on 10 September 2015. Strongly enhanced cold electron fluxes in the energy spectrogram were observed along with second harmonic mode waves with a period of about 1 min which lasted several hours during two consecutive Van Allen Probe B orbits. Cold electron (<200 eV) and energetic proton (10–20 keV) bidirectional pitch angle signatures observed during the event are suggestive of the drift‐bounce resonance mechanism. The correlation between enhanced energy fluxes and ULF waves leads to the conclusions that plasmaspheric dynamics is strongly affected by ULF waves. Van Allen Probe A and B, GOES 13, GOES 15, and MMS 1 observations suggest that ULF waves in the event were strongest on the duskside magnetosphere. Measurements from MMS 1 contain no evidence of an external wave source during the period when ULF waves and injected energetic protons with a bump‐on‐tail distribution were detected by Van Allen Probe B. This suggests that the observed ULF waves were probably excited by a localized drift‐bounce resonant instability, with the free energy supplied by substorm‐injected energetic protons. The observations by Van Allen Probe B suggest that energy transfer between particle species in different energy ranges can take place through the action of ULF waves, demonstrating the important role of these waves in the dynamical processes of the inner magnetosphere.

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“…So the residual PSD at the resonant pitch angles (30° and 150°) shows the inphase bidirectional pitch angle distributions in the upper panels of Figures a and c, which agrees with spacecraft observations(Ren, Zong, Zhou, et al, ; Yang, Zong, Fu, Takahashi, et al, ) and has an antiphase or inphase relationship with E Φ in the lower panels of Figures a and c, respectively. In Figures a and c, the phase shift across the resonant pitch angle is about 180° , which is difficult to be distinguished in observations due to phase mixing resulting from finite energy and pitch angle resolutions (Zhou et al, ), and spread resonant energies resulting from finite waveband width (Ren et al, ; Takahashi et al, ; Yang, Zong, Fu, Li, et al, ). The phase difference in Figure c is not close to 0°, which is associated with the ratio between the PSD variations related to the nonresonant effect (the term G 1 in equation ) and those related to the resonant effect (the term G 2 in equation ).…”

Section: Resultsmentioning

confidence: 96%

“…Both conventional and generalized drift resonant theories have successfully predicted and explained the behaviors of resonant particles and their relationship with ULF waves (e.g., Dai et al, ; Hao et al, ; Li et al, ; Southwood & Kivelson, ; Zhou et al, ). Recent studies start to explore drift‐bounce resonant particle's signatures in both energy and pitch angle spectra (Yang et al, ), and the energy transfer between waves and particles (Takahashi et al, ), which is based on the drift‐bounce resonant theory proposed by Southwood and Kivelson (, ).…”

Section: Introductionmentioning

confidence: 99%

Field‐Aligned Structures of the Poloidal‐Mode ULF Wave Electric Field: Phase Relationship Implications

et al. 2019

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Spacecraft observations within recent decades have demonstrated that ultralow frequency (ULF) waves play an important role in the dynamics of Earth's magnetosphere through drift and/or drift‐bounce resonance with different particle species. The phase relationship between resonant particles and waves can help us understand the wave‐particle interacting processes. It has been revealed that the phase relationship between the drift resonant particles and the fundamental poloidal‐mode electric field is a signature to judge the energy transfer direction between particles and waves, and the local phase space density gradient. Here we explore whether there are other physical meanings of the phase relationship for drift‐bounce resonant particles in addition to the similar ones as drift resonant particles. In this study, we find that (1) under different field‐aligned structures, the poloidal‐mode electric fields will show different phase relationship with drift‐bounce resonant particles at the magnetic equator. It indicates that the phase relationship can be used to diagnose the parallel morphologies of ULF wave electric field. (2) If particle's phase space density variations caused by resonance effect become more dominant while compared with the nonresonant effect, the phase difference becomes much closer to inphase or antiphase. (3) When wave's parallel morphology is given, the phase relationship can be used to judge the energy transfer direction between waves and particles. These findings can provide new sights into exploring ULF waves' propagation and distribution along magnetic field lines and studying their interaction with charged particles in the magnetosphere.

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Charged particle behavior in the growth and damping stages of ultralow frequency waves: Theory and Van Allen Probes observations

Cited by 59 publications

References 47 publications

Drift‐Bounce Resonance Between Charged Particles and Ultralow Frequency Waves: Theory and Observations

Drift‐Bounce Resonance Between Charged Particles and Ultralow Frequency Waves: Theory and Observations

Low‐Energy (<200 eV) Electron Acceleration by ULF Waves in the Plasmaspheric Boundary Layer: Van Allen Probes Observation

Field‐Aligned Structures of the Poloidal‐Mode ULF Wave Electric Field: Phase Relationship Implications

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