Pitch angle evolutions of oxygen ions driven by storm time ULF poloidal standing waves

Yang, Bojun; Zong, Qiugang; Fu, S. Y.; Takahashi, Kazue; Li, X.; Wang, Y. F.; Pu, Z. Y.; Fu, Huishan; Rème, H.; Yue, Chao; Zheng, Huinan; Sheng, Cheng

doi:10.1029/2010ja016047

Cited by 37 publications

(79 citation statements)

References 29 publications

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“…Yang et al (2011), especially in that they both show the inclined stripes in the pitch angle spectrum. Yang et al (2011), especially in that they both show the inclined stripes in the pitch angle spectrum.…”

Section: Summary and Discussionmentioning

confidence: 96%

“…After that, several attempts have been made to identify the occurrence Figure 6. Yang et al, 2010;B. (a, b) Three components of the magnetic and electric field in the GSM coordinates; (c-e) pitch angle spectra of ion energy fluxes at multiple energy channels centered at 5.9, 4.6, and 3.5 keV; (f) Azimuthal electric field E (red line) and radial magnetic field B r (black line) in the mean field-aligned coordinates; (g-i) pitch angle spectra of residual ion PSDs at multiple energy channels.…”

Section: Summary and Discussionmentioning

confidence: 99%

“…Yang et al (2011), observations of the Cluster spacecraft have been shown with quasiperiodic, recurring stripes in the pitch angle spectrum of oxygen ions at multiple energy channels. In B.…”

Section: 1029/2019ja027067mentioning

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: Summary and Discussionmentioning

confidence: 96%

Section: Summary and Discussionmentioning

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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“…Instead, we need to deduce the morphology of the ion pitch angle distributions at the equatorial region. Yang et al [2011] have interpreted the formation of these periodic pitch angle dispersion signatures. They are believed to evolve from periodic "in-phase" field-aligned O + beams at the equator generated through resonance with ULF waves.…”

Section: Derivation Of O + Equatorial Pitch Anglementioning

confidence: 99%

The role of ULF waves interacting with oxygen ions at the outer ring current during storm times

Yang

Zong

et al. 2011

J. Geophys. Res.

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[1] The modulations of the outer ring current O + ion fluxes by ULF Pc5 waves are investigated by multisatellite observations during storm times. The O + ions have energies up to tens of keV. We concentrate on the process in terms of drift-bounce resonance of O + ions with ULF standing waves to understand whether the ring current O + ions could be accelerated/decelerated by ULF waves. Two case studies are performed, in which the Cluster satellites travel the outer ring current region in the morning sector with radial distances of about 5.5 R E . Distinct O + ion flux oscillations are observed associated with fundamental mode ULF standing waves. On 25 October 2002, both satellites SC1 and SC4 observe strong poloidal and toroidal standing waves at approximately the same region one by one with a time lag of 45 min. The O + ion flux oscillations at around 20 keV are dominantly coherent with the poloidal standing wave at 3.4 mHz with cross phases of near 90°with respect to the magnetic field waves. The O + phase space density spectra at 10 to 25 keV, measured by both satellites, deviate significantly from the typical power law distribution. We suggest that the O + ions at 10 to 25 keV are accelerated due to drift-bounce resonance with the poloidal standing wave. On 4 November 2002, satellite SC1 observes considerable poloidal and toroidal standing waves. The O + ion flux oscillation at around 7 keV is well correlated with both of the two wave modes at 3.7 mHz with cross phases of about 90°with respect to the magnetic field waves. The O + spectra at 4 to 8 keV deviates remarkably from the background power law distribution. When satellite SC4 closely encounters the same region 40 min later, the wave activities at 3.7 mHz are found to be rather weak and the O + spectra is close to the background power law distribution. We suggest that the spectra variation of SC1 results from the deceleration of O + ion at 4 to 8 keV via drift-bounce resonances during the strong wave activities. The observations made in this study reveal the effective role of ULF standing waves in accelerating/decelerating the ring current O + ions.Citation: Yang, B., Q.-G. Zong, S. Y. Fu, X. Li, A. Korth, H. S. Fu, C. Yue, and H. Reme (2011), The role of ULF waves interacting with oxygen ions at the outer ring current during storm times,

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“…Such a mechanism has been described theoretically by Southwood and Kivelson [, ] and is possible because of the comparable periods of drift and bounce motion of energetic particles and ULF oscillations. As reported by Yang et al [] and Zong et al [], the associated damping takes place over time intervals where wave electric fields accelerate charged particles, a process that can also enhance radial diffusion [e.g., Loto'aniu et al , ]. Although energetic particle drift‐bounce resonance may occur with different ULF modes, e.g., toroidal ULF waves [ Elkington et al , ] and compressional poloidal‐mode ULF waves [ Elkington et al , , , ; Tan et al , ], the interaction with poloidal ULF waves [ Zong et al , , , ] is considered to be more efficient [ Zong et al , ; Yang et al , ; Zong et al , ], even leading to the formation of a new radiation belt [ Li et al , ; Wygant et al , ; Zong et al , ] in certain situations.…”

Section: Introductionmentioning

confidence: 99%

Fast damping of ultralow frequency waves excited by interplanetary shocks in the magnetosphere

2015

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Analysis of Cluster spacecraft data shows that intense ultralow frequency (ULF) waves in the inner magnetosphere can be excited by the impact of interplanetary shocks and solar wind dynamic pressure variations. The observations reveal that such waves can be damped away rapidly in a few tens of minutes. Here we examine mechanisms of ULF wave damping for two interplanetary shocks observed by Cluster on 7 November 2004 and 30 August 2001. The mechanisms considered are ionospheric joule heating, Landau damping, and waveguide energy propagation. It is shown that Landau damping provides the dominant ULF wave damping for the shock events of interest. It is further demonstrated that damping is caused by drift‐bounce resonance with ions in the energy range of a few keV. Landau damping is shown to be more effective in the plasmasphere boundary layer due to the higher proportion of Landau resonant ions that exist in that region.

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Pitch angle evolutions of oxygen ions driven by storm time ULF poloidal standing waves

Cited by 37 publications

References 29 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

The role of ULF waves interacting with oxygen ions at the outer ring current during storm times

Fast damping of ultralow frequency waves excited by interplanetary shocks in the magnetosphere

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