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Van Allen Probes Bibliography is from August 2012 through September 2021
Found 32 entries in the Bibliography.
Showing entries from 1 through 32
Statistics of Magnetosonic Waves in the Slot Region Observed by Van Allen Probes
Abstract We perform a statistical analysis of magnetosonic waves in the slot region based on Van Allen Probes observations from September 2012 to February 2018. Our results demonstrate that the wave occurrence rate increases with enhanced geomagnetic activity and decreasing magnetic latitude, with the presence of strongest slot region magnetosonic waves near the geomagnetic equator within the 08-20 MLT sector. Power spectral densities of slot region magnetosonic waves also intensify during geomagnetically active times, with ...
Yan, Ling; Cao, Xing; Hua, Man; Ni, Binbin; Zhang, Yuannong;
Published by: Geophysical Research Letters Published on: 06/2021
YEAR: 2021   DOI: https://doi.org/10.1029/2021GL094015
magnetosonic waves; Slot region; Statistical distribution; Van Allen Probes
Empirical loss timescales of slot region electrons due to plasmaspheric hiss based on Van Allen Probes observations
Abstract Based on Van Allen Probes observations, in this study we perform a statistical analysis of the spectral intensities of plasmaspheric hiss at L-shells of 1.8 – 3.0 in the slot region. Our results show that slot region hiss power intensifies with a strong day-night asymmetry as the level of substorm activity or L-shell increases. Using the statistical spectral profiles of plasmaspheric hiss, we calculate the drift- and bounce-averaged electron pitch angle diffusion coefficients and subsequently obtain the resultant ...
Zhu, Qi; Cao, Xing; Gu, Xudong; Ni, Binbin; Xiang, Zheng; Fu, Song; Summers, Danny; Hua, Man; Lou, Yuequn; Ma, Xin; Guo, YingJie; Guo, DeYu; Zhang, Wenxun;
Published by: Journal of Geophysical Research: Space Physics Published on: 04/2021
YEAR: 2021   DOI: https://doi.org/10.1029/2020JA029057
Plasmaspheric Hiss; Slot region; Electron loss timescales; Van Allen Probes
Prediction of Dynamic Plasmapause Location Using a Neural Network
Abstract As a common boundary layer that distinctly separates the regions of high-density plasmasphere and low-density plasmatrough, the plasmapause is essential to comprehend the dynamics and variability of the inner magnetosphere. Using the machine learning framework Pytorch and high-quality Van Allen Probes data set, we develop a neural network model to predict the global dynamic variation of the plasmapause location, along with the identification of 6537 plasmapause crossing events during the period from 2012 to 2017. To ...
Guo, DeYu; Fu, Song; Xiang, Zheng; Ni, Binbin; Guo, YingJie; Feng, Minghang; Guo, JianGuang; Hu, Zejun; Gu, Xudong; Zhu, Jianan; Cao, Xing; Wang, Qi;
Published by: Space Weather Published on: 03/2021
YEAR: 2021   DOI: https://doi.org/10.1029/2020SW002622
Plasmapause; neural network; Van Allen Probes; space weather forecast
Global distribution of reversed energy spectra of ring current protons based on Van Allen Probes observations
Abstract Energy spectra of ring current protons are crucial to understanding the ring current dynamics. Based on high-quality Van Allen Probes RBSPICE measurements, we investigate the global distribution of the reversed proton energy spectra using the 2013-2019 RBSPICE datasets. The reversed proton energy spectra are characterized by the distinct flux minima around 50 - 100 keV and flux maxima around 200 - 400 keV. Our results show that the reversed proton energy spectrum is prevalent inside the plasmasphere, with the occurr ...
Juan, Yi; Song, Fu; Binbin, Ni; Xudong, Gu; Hua, Man; Xiang, Zheng; Cao, Xing; Shi, Run; Zhao, Yiwen;
Published by: Geophysical Research Letters Published on: 01/2021
YEAR: 2021   DOI: https://doi.org/10.1029/2020GL091559
Statistical Distribution of Bifurcation of Earth s Inner Energetic Electron Belt at tens of keV
We present a survey of the bifurcation of the Earth s energetic electron belt (tens of keV) using 6-year measurements from Van Allen Probes. The inner energetic electron belt usually presents one-peak radial structure with high flux intensity at L < ∼2.5, which however can be bifurcated to exhibit a double-peak radial structure. By automatically identifying the events of bifurcation based on RBSPICE data, we find that the bifurcation is mostly observed at ∼30–100 keV with a local flux minimum at L=∼2.0–∼2.3 under ...
Hua, Man; Ni, Binbin; Li, Wen; Ma, Qianli; Gu, Xudong; Fu, Song; Cao, Xing; Guo, YingJie; Liu, Yangxizi;
Published by: Geophysical Research Letters Published on: 12/2020
YEAR: 2020   DOI: https://doi.org/10.1029/2020GL091242
Inner electron radiation belt; Flux bifurcation; VLF transmitter waves; Statistical distribution; Van Allen Probes
On the loss mechanisms of radiation belt electron dropouts during the 12 September 2014 geomagnetic storm
Radiation belt electron dropouts indicate electron flux decay to the background level during geomagnetic storms, which is commonly attributed to the effects of wave-induced pitch angle scattering and magnetopause shadowing. To investigate the loss mechanisms of radiation belt electron dropouts triggered by a solar wind dynamic pressure pulse event on 12 September 2014, we comprehensively analyzed the particle and wave measurements from Van Allen Probes. The dropout event was divided into three periods: before the storm, the ...
Ma, Xin; Xiang, Zheng; Ni, Binbin; Fu, Song; Cao, Xing; Hua, Man; Guo, DeYu; Guo, YingJie; Gu, Xudong; Liu, ZeYuan; Zhu, Qi;
Published by: Earth and Planetary Physics Published on: 11/2020
YEAR: 2020   DOI: https://doi.org/10.26464/epp2020060
radiation belt electron flux dropouts; Geomagnetic storm; electron phase space density; magnetopause shadowing; wave–particle interactions; Van Allen Probes
Precipitation Loss of Radiation Belt Electrons by Two-Band Plasmaspheric Hiss Waves
A two-band plasmaspheric hiss consisting of a low-frequency band (normal hiss with the frequency below 2 kHz) and a high-frequency band (locally generated hiss with the frequency up to 10 kHz) was observed on 6 January 2014 by the Van Allen Probes (He et al., 2019, https://doi.org/10.1029/2018GL081578). The electron scattering effect driven by this kind of two-band plasmaspheric hiss is evaluated by the quasi-linear diffusion simulation for the first time. Realistic wave characteristic parameters of the two-band plasmasp ...
He, Zhaoguo; Yan, Qi; Zhang, Xiaoping; Yu, Jiang; Ma, Yonghui; Cao, Yong; Cui, Jun;
Published by: Journal of Geophysical Research: Space Physics Published on: 10/2020
YEAR: 2020   DOI: https://doi.org/10.1029/2020JA028157
two-band hiss; radiation belt electron; loss; Van Allen Probes
Electron Diffusion by Coexisting Plasmaspheric Hiss and Chorus Waves: Multisatellite Observations and Simulations
We report a rare event of intense plasmaspheric hiss and chorus waves simultaneously observed at the same L shell but different magnetic local times by Van Allen Probes and Magnetospheric Multiscale. Based on the measured waves and electron distributions, we calculate the bounce-averaged diffusion coefficients and subsequently simulate the temporal evolution of electron distributions. The simulations show that the dynamics of tens to hundreds of keV electrons are jointly controlled by hiss and chorus. The dynamics of MeV ele ...
Yu, J.; Wang, J.; Li, L; Cui, J.; Cao, J.; He, Z.;
Published by: Geophysical Research Letters Published on: 07/2020
YEAR: 2020   DOI: https://doi.org/10.1029/2020GL088753
electron diffusion; Plasmaspheric Hiss; chorus waves; Van Allen Probes; MMS
Effects of Solar Wind Plasma Flow and Interplanetary Magnetic Field on the Spatial Structure of Earth\textquoterights Radiation Belts
Based on the statistical data measured by Van Allen Probes from 2012 to 2016, we analyzed the effects of solar wind plasma flow and interplanetary magnetic field (IMF) on the spatial distribution of Earth\textquoterights radiation belt electrons (>100 keV). The statistical results indicate that the increases in solar wind plasma density and flow speed can exert different effects on the spatial structure of the radiation belts. The high solar wind plasma density (>6 cm-3)/flow pressure (>2.5 nPa) and a large southward IMF (Bz ...
Li, L.Y.; Yang, S.S.; Cao, J.B.; Yu, J.; Luo, X.Y.; Blake, J.B.;
Published by: Journal of Geophysical Research: Space Physics Published on: 12/2019
YEAR: 2019   DOI: 10.1029/2019JA027284
Changes in The Spatial Structure of Earth\textquoterights Radiation Belts; Increase in Solar Wind Plasma Density; Increase in Solar Wind Plasma Flow Speed; Northward Interplanetary Magnetic Field; Southward interplanetary magnetic field; Van Allen Probes
Wave Normal Angle Distribution of Fast Magnetosonic Waves: A Survey of Van Allen Probes EMFISIS Observations
Using Van Allen Probe Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) wave observations from September 2012 to May 2018, we statistically investigate the distributions of power-weighted wave normal angle (WNA) of fast magnetosonic (MS) waves from L = 2\textendash6 within \textpm15\textdegree geomagnetic latitudes. The spatial distributions show that the MS WNAs are mainly confined within 87\textendash89\textdegree near the geomagnetic equator and decrease with increasing magnetic latitude. Furth ...
Zou, Zhengyang; Zuo, Pingbing; Ni, Binbin; Wei, Fengsi; Zhao, Zhengyu; Cao, Xing; Fu, Song; Gu, Xudong;
Published by: Journal of Geophysical Research: Space Physics Published on: 07/2019
YEAR: 2019   DOI: 10.1029/2019JA026556
Empirical Model; Fast Magnetosonic Waves; latitudinal dependence; power-weighted wave normal angles; spatial distributions; Van Allen Probes
Effect of Low-Harmonic Magnetosonic Waves on the Radiation Belt Electrons Inside the Plasmasphere
In this paper, we presented two observational cases and simulations to indicate the relationship between the formation of butterfly-like electron pitch angle distributions and the emission of low-harmonic (LH) fast magnetosonic (MS) waves inside the high-density plasmasphere. In the wave emission region, the pitch angle of relativistic (>1 MeV) electrons becomes obvious butterfly-like distributions for both events (near-equatorially mirroring electrons are transported to lower pitch angles). Unlike relativistic (>1 MeV) elec ...
Yu, J.; Li, L; Cui, J.; Cao, J.; Wang, J.;
Published by: Journal of Geophysical Research: Space Physics Published on: 05/2019
YEAR: 2019   DOI: 10.1029/2018JA026328
bounce resonance; Electron acceleration; Landau resonance; magnetosonic waves; transit-time scattering; Van Allen Probes
Statistical Properties of Hiss in Plasmaspheric Plumes and Associated Scattering Losses of Radiation Belt Electrons
Whistler mode hiss acts as an important loss mechanism contributing to the radiation belt electron dynamics inside the plasmasphere and plasmaspheric plumes. Based on Van Allen Probes observations from September 2012 to December 2015, we conduct a detailed analysis of hiss properties in plasmaspheric plumes and illustrate that corresponding to the highest occurrence probability of plumes at L = 5.0\textendash6.0 and MLT = 18\textendash21, hiss emissions occur concurrently with a rate of >~80\%. Plume hiss can efficiently sca ...
Zhang, Wenxun; Ni, Binbin; Huang, He; Summers, Danny; Fu, Song; Xiang, Zheng; Gu, Xudong; Cao, Xing; Lou, Yuequn; Hua, Man;
Published by: Geophysical Research Letters Published on: 05/2019
YEAR: 2019   DOI: 10.1029/2018GL081863
Electron scattering; plasmaspheric plumes; plume hiss; Van Allen Probes
Local Generation of High-Frequency Plasmaspheric Hiss Observed by Van Allen Probes
The generation of a high-frequency plasmaspheric hiss (HFPH) wave observed by Van Allen Probes is studied in this letter for the first time. The wave has a moderate power spectral density (\~10-6 nT2/Hz), with a frequency range extended from 2 to 10 kHz. The correlated observations of waves and particles indicate that HFPH is associated with the enhancement of electron flux during the substorm on 6 January 2014. Calculations of the wave linear growth rate driven by the fitted electron phase space density show that the electr ...
He, Zhaoguo; Chen, Lunjin; Liu, Xu; Zhu, Hui; Liu, Si; Gao, Zhonglei; Cao, Yong;
Published by: Geophysical Research Letters Published on: 01/2019
YEAR: 2019   DOI: 10.1029/2018GL081578
electron; high frequency; local generation; Plasmaspheric Hiss; substorm injection; Van Allen Probes
Sensitivity of EMIC Wave-Driven Scattering Loss of Ring Current Protons to Wave Normal Angle Distribution
Electromagnetic ion cyclotron waves have long been recognized to play a crucial role in the dynamic loss of ring current protons. While the field-aligned propagation approximation of electromagnetic ion cyclotron waves was widely used to quantify the scattering loss of ring current protons, in this study, we find that the wave normal distribution strongly affects the pitch angle scattering efficiency of protons. Increase of peak normal angle or angular width can considerably reduce the scattering rates of <=10 keV protons. F ...
Cao, Xing; Ni, Binbin; Summers, Danny; Shprits, Yuri; Gu, Xudong; Fu, Song; Lou, Yuequn; Zhang, Yang; Ma, Xin; Zhang, Wenxun; Huang, He; Yi, Juan;
Published by: Geophysical Research Letters Published on: 01/2019
YEAR: 2019   DOI: 10.1029/2018GL081550
EMIC waves; Quasi-linear diffusion; Ring current protons; Van Allen Probes; wave-particle interactions
Combined Scattering of Outer Radiation Belt Electrons by Simultaneously Occurring Chorus, Exohiss, and Magnetosonic Waves
We report a typical event that fast magnetosonic (MS) waves, exohiss, and two-band chorus waves occurred simultaneously on the dayside observed by Van Allen Probes on 25 December 2013. By combining calculations of electron diffusion coefficients and 2-D Fokker-Planck diffusion simulations, we quantitatively analyze the combined scattering effect of multiple waves to demonstrate that the net impact of combined scattering does not simply depend on the wave intensity dominance of various plasma waves. Although the observed MS w ...
Hua, Man; Ni, Binbin; Fu, Song; Gu, Xudong; Xiang, Zheng; Cao, Xing; Zhang, Wenxun; He, Ying; Huang, He; Lou, Yuequn; Zhang, Yang;
Published by: Geophysical Research Letters Published on: 09/2018
YEAR: 2018   DOI: 10.1029/2018GL079533
Combined scattering effect; diffusion simulations; Exohiss; magnetosonic waves; resonant wave-particle interactions; two-band chorus waves; Van Allen Probes
A Statistical Survey of Radiation Belt Dropouts Observed by Van Allen Probes
A statistical analysis on the radiation belt dropouts is performed based on 4 years of electron phase space density data from the Van Allen Probes. The μ, K, and L* dependence of dropouts and their driving mechanisms and geomagnetic and solar wind conditions are investigated using electron phase space density data sets for the first time. Our results suggest that electronmagnetic ion cyclotron (EMIC) wave scattering is the dominant dropout mechanism at low L* region, which requires the most active geomagnetic and solar wind ...
Xiang, Zheng; Tu, Weichao; Ni, Binbin; Henderson, M.; Cao, Xing;
Published by: Geophysical Research Letters Published on: 08/2018
YEAR: 2018   DOI: 10.1029/2018GL078907
EMIC wave; magnetopause shadowing; Phase space density; radial diffusion; radiation belt dropout; Van Allen Probes; wave particle interaction
Electron Scattering by Plasmaspheric Hiss in a Nightside Plume
Plasmaspheric hiss is known to play an important role in radiation belt electron dynamics in high plasma density regions. We present observations of two crossings of a plasmaspheric plume by the Van Allen Probes on 26 December 2012, which occurred unusually at the post-midnight-to-dawn sector between L ~ 4\textendash6 during a geomagnetically quiet period. This plume exhibited pronounced electron densities higher than those of the average plume level. Moderate hiss emissions accompanied the two plume crossings with the peak ...
Zhang, Wenxun; Fu, Song; Gu, Xudong; Ni, Binbin; Xiang, Zheng; Summers, Danny; Zou, Zhengyang; Cao, Xing; Lou, Yuequn; Hua, Man;
Published by: Geophysical Research Letters Published on: 05/2018
YEAR: 2018   DOI: 10.1029/2018GL077212
Electron scattering; nightside plumes; Plasmaspheric Hiss; Van Allen Probes
Resonant Scattering of Radiation Belt Electrons by Off-Equatorial Magnetosonic Waves
Fast magnetosonic (MS) waves are commonly regarded as electromagnetic waves that are characteristically confined within \textpm3\textdegree of the geomagnetic equator. We report two typical off-equatorial MS events observed by Van Allen Probes, that is, the 8 May 2014 event that occurred at the geomagnetic latitudes of 7.5\textdegree\textendash9.2\textdegree both inside and outside the plasmasphere with the wave amplitude up to 590 pT and the 9 January 2014 event that occurred at the latitudes of\textemdash(15.7\textdegree\t ...
Ni, Binbin; Zou, Zhengyang; Fu, Song; Cao, Xing; Gu, Xudong; Xiang, Zheng;
Published by: Geophysical Research Letters Published on: 02/2018
YEAR: 2018   DOI: 10.1002/grl.v45.310.1002/2017GL075788
butterfly pitch angle distributions; off-equatorial MS waves; radiation belt electrons; Van Allen Probes
The Effect of Hot Protons on Magnetosonic Waves Inside and Outside the Plasmapause: New Observations and Theoretic Results
Based on the wave and proton observations by Van Allen Probes A and B, we examined the effects of hot protons (0.01\textendash50 keV) on fast magnetosonic (MS) waves inside and outside the Earth\textquoterights plasmasphere. In the low-density plasma trough outside the plasmapause, the gyroresonance interactions between hot protons and MS waves not only cause the MS wave growth at some frequencies but also lead to the damping of MS waves at other frequencies, which depends on the proton phase space density gradient and the a ...
Liu, Bin; Li, Liuyuan; Yu, Jiang; Cao, Jinbin;
Published by: Journal of Geophysical Research: Space Physics Published on: 01/2018
YEAR: 2018   DOI: 10.1002/2017JA024676
damping of magnetosonic waves; growth of magnetosonic waves; magnetosonic waves; magnetospheric hot protons; Van Allen Probes; wave-particle interactions
Multiple-satellite observation of magnetic dip event during the substorm on 10 October, 2013
We present a multiple-satellite observation of the magnetic dip event during the substorm on October 10, 2013. The observation illustrates the temporal and spatial evolution of the magnetic dip and gives a compelling evidence that ring current ions induce the magnetic dip by enhanced plasma beta. The dip moves with the energetic ions in a comparable drift velocity and affects the dynamics of relativistic electrons in the radiation belt. In addition, the magnetic dip provides a favorable condition for the EMIC wave generation ...
He, Zhaoguo; Chen, Lunjin; Zhu, Hui; Xia, Zhiyang; Reeves, G.; Xiong, Ying; Xie, Lun; Cao, Yong;
Published by: Geophysical Research Letters Published on: 09/2017
YEAR: 2017   DOI: 10.1002/2017GL074869
EMIC wave; magnetic dip; radiation belt electrons; Ring current ions; Van Allen Probes
Bounce resonance scattering of radiation belt electrons by low-frequency hiss: Comparison with cyclotron and Landau resonances
Bounce-resonant interactions with magnetospheric waves have been proposed as important contributing mechanisms for scattering near-equatorially mirroring electrons by violating the second adiabatic invariant associated with the electron bounce motion along a geomagnetic field line. This study demonstrates that low-frequency plasmaspheric hiss with significant wave power below 100 Hz can bounce-resonate efficiently with radiation belt electrons. By performing quantitative calculations of pitch-angle scattering rates, we show ...
Cao, Xing; Ni, Binbin; Summers, Danny; Zou, Zhengyang; Fu, Song; Zhang, Wenxun;
Published by: Geophysical Research Letters Published on: 09/2017
YEAR: 2017   DOI: 10.1002/2017GL075104
bounce resonance; Low-frequency hiss; Radiation Belt Dynamics; Van Allen Probes; wave-particle interactions
Propagation characteristics of plasmaspheric hiss: Van Allen Probe observations and global empirical models
Based on the Van Allen Probe A observations from 1 October 2012 to 31 December 2014, we develop two empirical models to respectively describe the hiss wave normal angle (WNA) and amplitude variations in the Earth\textquoterights plasmasphere for different substorm activities. The long-term observations indicate that the plasmaspheric hiss amplitudes on the dayside increase when substorm activity is enhanced (AE index increases), and the dayside hiss amplitudes are greater than the nightside. However, the propagation angles ( ...
Yu, J.; Li, L; Cao, J.; Chen, L.; Wang, J.; Yang, J.;
Published by: Journal of Geophysical Research: Space Physics Published on: 04/2017
YEAR: 2017   DOI: 10.1002/2016JA023372
hiss amplitude model; hiss wave amplitude; Plasmaspheric Hiss; propagation angle model of hiss waves; substorm dependence; Van Allen Probes; wave normal angle
Roles of whistler-mode waves and magnetosonic waves in changing the outer radiation belt and the slot region
Using the Van Allen Probe long-term (2013 \textendash 2015) observations and quasi-linear simulations of wave-particle interactions, we examine the combined or competing effects of whistler-mode waves (chorus or hiss) and magnetosonic (MS) waves on energetic (<0.5 MeV) and relativistic (>0.5 MeV) electrons inside and outside the plasmasphere. Although whistler-mode chorus waves and MS waves can singly or jointly accelerate electrons from the hundreds of keV energy to the MeV energy in the low-density trough, most of the rela ...
Li, L; Yu, J.; Cao, J.; Yang, J; Li, X.; Baker, D.; Reeves, G.; Spence, H.;
Published by: Journal of Geophysical Research: Space Physics Published on: 04/2017
YEAR: 2017   DOI: 10.1002/2016JA023634
magnetosonic waves; Plasmapause movement; Spatial variation of outer radiaton belt; Spatial variation of slot region; Temporal-spatial variations of chorus waves; Temporal-spatial variations of plasmaspheric hiss; Van Allen Probes
Inferring electromagnetic ion cyclotron wave intensity from low altitude POES proton flux measurements: A detailed case study with conjugate Van Allen Probes observations
Zhang, Yang; Shi, Run; Ni, Binbin; Gu, Xudong; Zhang, Xianguo; Zuo, Pingbing; Fu, Song; Xiang, Zheng; Wang, Qi; Cao, Xing; Zou, Zhengyang;
Published by: Advances in Space Research Published on: 03/2017
YEAR: 2017   DOI: 10.1016/j.asr.2016.12.035
A new method to study the time correlation between Van Allen Belt electrons and earthquakes
A new method to study a possible temporal correlation between hundreds of keV Van Allen Belt electrons and strong earthquakes is proposed. It consists in measuring the electrons pitch angle distribution (PAD), searching for PAD disturbances, and studying the time correlation between these PAD disturbances and strong earthquakes, occurring within a defined time window. The method was applied to measurements of energetic electrons, which were performed with the Energetic Particle, Composition, and Thermal Plasma (ECT)-MagEIS d ...
Tao, Dan; Battiston, Roberto; Vitale, Vincenzo; Burger, William; Lazzizzera, Ignazio; Cao, Jinbin; Shen, Xuhui;
Published by: International Journal of Remote Sensing Published on: 10/2016
YEAR: 2016   DOI: 10.1080/01431161.2016.1239284
Wave-driven gradual loss of energetic electrons in the slot region
Resonant pitch angle scattering by plasmaspheric hiss has long been considered to be responsible for the energetic electron loss in the slot region, but the detailed quantitative comparison between theory and observations is still lacking. Here we focus on the loss of 100\textendash600 keV electrons at L = 3 during the recovery phase of a geomagnetic storm on 28 June 2013. Van Allen Probes data showed the concurrence of intense (with power up to 10-4 nT2/Hz) plasmaspheric hiss waves and significant (up to 1 order) loss of en ...
He, Zhaoguo; Yan, Qi; Chu, Yuchuan; Cao, Yong;
Published by: Journal of Geophysical Research: Space Physics Published on: 09/2016
YEAR: 2016   DOI: 10.1002/2016JA023087
electron loss; energetic electron; Plasmaspheric Hiss; Slot region; Van Allen Probes; Wave-particle interaction
The influences of solar wind pressure and interplanetary magnetic field on global magnetic field and outer radiation belt electrons
Using the Van Allen Probe in-situ measured magnetic field and electron data, we examine the solar wind dynamic pressure and interplanetary magnetic field (IMF) effects on global magnetic field and outer radiation belt relativistic electrons (>=1.8 MeV). The dynamic pressure enhancements (>2nPa) cause the dayside magnetic field increase and the nightside magnetic field reduction, whereas the large southward IMFs (Bz-IMF < -2nT) mainly lead to the decrease of the nightside magnetic field. In the dayside increased magnetic fiel ...
Yu, J.; Li, L.Y.; Cao, J.; Reeves, G.; Baker, D.; Spence, H.;
Published by: Geophysical Research Letters Published on: 06/2016
YEAR: 2016   DOI: 10.1002/2016GL069029
butterfly distributions; Day-night asymmetrical variations of magnetic field; Day-night asymmetrical variations of relativistic electron pitch angle distributions; Pancake distributions; solar wind dynamic pressure; Southward interplanetary magnetic field; Van Allen Probes
Combined Scattering Loss of Radiation Belt Relativistic Electrons by Simultaneous Three-band EMIC Waves: A Case Study
Multiband electromagnetic ion cyclotron (EMIC) waves can drive efficient scattering loss of radiation belt relativistic electrons. However, it is statistically uncommon to capture the three bands of EMIC waves concurrently. Utilizing data from the Electric and Magnetic Field Instrument Suite and Integrated Science magnetometer onboard Van Allen Probe A, we report the simultaneous presence of three (H+, He+, and O+) emission bands in an EMIC wave event, which provides an opportunity to look into the combined scattering effect ...
He, Fengming; Cao, Xing; Ni, Binbin; Xiang, Zheng; Zhou, Chen; Gu, Xudong; Zhao, Zhengyu; Shi, Run; Wang, Qi;
Published by: Journal of Geophysical Research: Space Physics Published on: 05/2016
YEAR: 2016   DOI: 10.1002/2016JA022483
combined scattering rates; electromagnetic ion cyclotron waves; loss timescales; radiation belt relativistic electrons; resonant wave-particle interactions; Van Allen Probes
Observations of discrete magnetosonic waves off the magnetic equator
Fast mode magnetosonic waves are typically confined close to the magnetic equator and exhibit harmonic structures at multiples of the local, equatorial proton cyclotron frequency. We report observations of magnetosonic waves well off the equator at geomagnetic latitudes from -16.5\textdegreeto -17.9\textdegree and L shell ~2.7\textendash4.6. The observed waves exhibit discrete spectral structures with multiple frequency spacings. The predominant frequency spacings are ~6 and 9 Hz, neither of which is equal to the local proto ...
Zhima, Zeren; Chen, Lunjin; Fu, Huishan; Cao, Jinbin; Horne, Richard; Reeves, Geoff;
Published by: Geophysical Research Letters Published on: 12/2015
YEAR: 2015   DOI: 10.1002/2015GL066255
Multiple loss processes of relativistic electrons outside the heart of outer radiation belt during a storm sudden commencement
By examining the compression-induced changes in the electron phase space density and pitch angle distribution observed by two satellites of Van Allen Probes (RBSP-A/B), we find that the relativistic electrons (>2MeV) outside the heart of outer radiation belt (L*>= 5) undergo multiple losses during a storm sudden commencement (SSC). The relativistic electron loss mainly occurs in the field-aligned direction (pitch angle α< 30\textdegree or >150\textdegree), and the flux decay of the field-aligned electrons is independent of ...
Yu, J.; Li, L.Y.; Cao, J.; Yuan, Z.; Reeves, G.; Baker, D.; Blake, J.; Spence, H.;
Published by: Journal of Geophysical Research: Space Physics Published on: 11/2015
YEAR: 2015   DOI: 10.1002/2015JA021460
Electromagnetic ion cyclotron (EMIC) waves; outer radiation belt; Outward radial diffusion driven by ULF waves; Plasmaspheric Hiss; relativistic electron loss; Storm sudden commencement; Van Allen Probes
Resonant scattering of outer zone relativistic electrons by multiband EMIC waves and resultant electron loss time scales
To improve our understanding of the role of electromagnetic ion cyclotron (EMIC) waves in radiation belt electron dynamics, we perform a comprehensive analysis of EMIC wave-induced resonant scattering of outer zone relativistic (>0.5 MeV) electrons and resultant electron loss time scales with respect to EMIC wave band, L shell, and wave normal angle model. The results demonstrate that while H+-band EMIC waves dominate the scattering losses of ~1\textendash4 MeV outer zone relativistic electrons, it is He+-band and O+-band wa ...
Ni, Binbin; Cao, Xing; Zou, Zhengyang; Zhou, Chen; Gu, Xudong; Bortnik, Jacob; Zhang, Jichun; Fu, Song; Zhao, Zhengyu; Shi, Run; Xie, Lun;
Published by: Journal of Geophysical Research: Space Physics Published on: 09/2015
YEAR: 2015   DOI: 10.1002/2015JA021466
electron loss time scales; EMIC waves; outer radiation belt; relativistic electrons; resonant wave-particle interactions
First observation of rising-tone magnetosonic waves
Magnetosonic (MS) waves are linearly polarized emissions confined near the magnetic equator with wave normal angle near 90\textdegree and frequency below the lower hybrid frequency. Such waves, also termed equatorial noise, were traditionally known to be \textquotedbllefttemporally continuous\textquotedblright in their time-frequency spectrogram. Here we show for the first time that MS waves actually have discrete wave elements with rising-tone features in their spectrogram. The frequency sweep rate of MS waves, ~1 Hz/s, is ...
Fu, H.; Cao, J.; Zhima, Z.; Khotyaintsev, Y.; Angelopoulos, V.; ik, O.; Omura, Y.; Taubenschuss, U.; Chen, L.; Huang, S;
Published by: Geophysical Research Letters Published on: 11/2014
YEAR: 2014   DOI: 10.1002/grl.v41.2110.1002/2014GL061867
discrete; frequency sweep rate; magnetosonic wave; nonlinear wave-particle interaction; Plasmapause; rising tone