Bibliography



Found 40 entries in the Bibliography.


Showing entries from 1 through 40


2020

Quantifying the Effect of Plasmaspheric Hiss on the Electron Loss from the Slot Region

Abstract We present global statistical models of both wave amplitude and wave normal angle (WNA) of plasmaspheric hiss using Van Allen Probe-A observations. They utilize the time history of solar wind parameters, i.e., interplanetary magnetic field BZ and solar wind speed, and the AE index for each measurement of hiss waves as inputs. The solar wind parameter-based model generally results in higher performance than using only the AE index as an input. Both observations and model results reveal a clear dependence of hiss wave ...

Kim, Kyung-Chan; Shprits, Yuri; Wang, Dedong;

YEAR: 2020     DOI: 10.1029/2019JA027555

Plasmaspheric Hiss; Van Allen Probes; Electron slot region; Statistical modeling; Diffusion simulation; Wave-particle interaction

The Effect of Plasma Boundaries on the Dynamic Evolution of Relativistic Radiation Belt Electrons

Abstract Understanding the dynamic evolution of relativistic electrons in the Earth s radiation belts during both storm and nonstorm times is a challenging task. The U.S. National Science Foundation s Geospace Environment Modeling (GEM) focus group “Quantitative Assessment of Radiation Belt Modeling” has selected two storm time and two nonstorm time events that occurred during the second year of the Van Allen Probes mission for in-depth study. Here, we perform simulations for these GEM challenge events using the 3D Versa ...

Wang, Dedong; Shprits, Yuri; Zhelavskaya, Irina; Effenberger, Frederic; Castillo, Angelica; Drozdov, Alexander; Aseev, Nikita; Cervantes, Sebastian;

YEAR: 2020     DOI: 10.1029/2019JA027422

Radiation belt; simulation; relativistic electrons; magnetopause shadowing; Wave-particle interaction; Plasmapause; Van Allen Probes

2019

Rapid Precipitation of Relativistic Electron by EMIC Rising-Tone Emissions Observed by the Van Allen Probes

On 23 February 2014, Van Allen Probes sensors observed quite strong electromagnetic ion cyclotron (EMIC) waves in the outer dayside magnetosphere. The maximum amplitude was more than 14 nT, comparable to 7\% of the magnitude of the ambient magnetic field. The EMIC waves consisted of a series of coherent rising tone emissions. Rising tones are excited sporadically by energetic protons. At the same time, the probes detected drastic fluctuations in fluxes of MeV electrons. It was found that the electron fluxes decreased by more ...

Nakamura, S.; Omura, Y.; Kletzing, C.; Baker, D.;

YEAR: 2019     DOI: 10.1029/2019JA026772

EMIC waves; Magnetosphere; microburst; nonlinear; Radiation belt; Van Allen Probes; Wave-particle interaction

Cold Plasmaspheric Electrons Affected by ULF Waves in the Inner Magnetosphere: A Van Allen Probes Statistical Study

Six years of Van Allen Probes data are used to investigate cold plasmaspheric electrons affected by ultralow-frequency (ULF) waves in the inner magnetosphere (L<7) including spatial distributions, occurrence conditions, and resonant energy range. Events exhibit a global distribution within L= 4\textendash7 but preferentially occur at L\~5.5\textendash7 in the dayside, while there is higher occurrence rate in the duskside than dawnside. They can occur under different geomagnetic activities and solar wind velocities (VS), but ...

Ren, Jie; Zong, Q.; Zhou, X.; Spence, H.; Funsten, H.; Wygant, J.; Rankin, R.;

YEAR: 2019     DOI: 10.1029/2019JA027009

Cold plasmaspheric electrons; drift-bounce resonance; ULF waves; Van Allen Probes; Wave-particle interaction

Evaluation of Plasma Properties From Chorus Waves Observed at the Generation Region

In this study we present an inversion method which provides thermal plasma population parameters from characteristics of chorus emissions only. Our ultimate goal is to apply this method to ground-based data in order to derive the lower-energy boundary condition for many radiation belt models. The first step is to test the chorus inversion method on in situ data of the Van Allen Probes in the generation region. The density and thermal velocity of energetic electrons (few kiloelectron volts to 100 keV) are derived from frequen ...

asz, Lilla; Omura, Yoshiharu; Lichtenberger, J\; Friedel, Reinhard;

YEAR: 2019     DOI: 10.1029/2018JA026337

chorus inversion; Van Allen Probes; Wave-particle interaction

Quenching of Equatorial Magnetosonic Waves by Substorm Proton Injections

Near equatorial (fast) magnetosonic waves, characterized by high magnetic compressibility, are whistler-mode emissions destabilized by proton shell/ring distributions. In the past, substorm proton injections are widely known to intensify magnetosonic waves in the inner magnetosphere. Here we report the unexpected observations by the Van Allen Probes of the magnetosonic wave quenching associated with the substorm proton injections under both high- and low-density conditions. The enhanced proton thermal pressure distorted the ...

Dai, Guyue; Su, Zhenpeng; Liu, Nigang; Wang, Bin; Zheng, Huinan; Wang, Yuming; Wang, Shui;

YEAR: 2019     DOI: 10.1029/2019GL082944

Bernstein mode instability; magnetosonic wave; Radiation belt; ring current; substorm injection; Van Allen Probes; Wave-particle interaction

2018

Precipitation of radiation belt electrons by EMIC waves with conjugated observations of NOAA and Van Allen satellites

In this letter, we present unique conjugated satellite observations of MeV relativistic electron precipitation caused by electromagnetic ion cyclotron (EMIC) waves. On the outer boundary of the plasmasphere, the Van Allen probe observed EMIC waves. At ionospheric altitudes, the NOAA 16 satellite at the footprint of Van Allen probe simultaneously detected obvious flux enhancements for precipitating >MeV radiation belt electrons, but not for precipitating

Yuan, Zhigang; Liu, Kun; Yu, Xiongdong; Yao, Fei; Huang, Shiyong; Wang, Dedong; Ouyang, Zhihai;

YEAR: 2018     DOI: 10.1029/2018GL080481

Chorus; EMIC waves; Particle precipitation; Radiation belt; ring current; Van Allen Probes; Wave-particle interaction

Diagnosis of ULF Wave-Particle Interactions With Megaelectron Volt Electrons: The Importance of Ultrahigh-Resolution Energy Channels

Electron flux measurements are an important diagnostic for interactions between ultralow-frequency (ULF) waves and relativistic (\~1 MeV) electrons. Since measurements are collected by particle detectors with finite energy channel width, they are affected by a phase mixing process that can obscure these interactions. We demonstrate that ultrahigh-resolution electron measurements from the Magnetic Electron Ion Spectrometer on the Van Allen Probes mission\textemdashobtained using a data product that improves the energy resolut ...

Hartinger, M.; Claudepierre, S.; Turner, D.; Reeves, G.; Breneman, A.; Mann, I.; Peek, T.; Chang, E.; Blake, J.; Fennell, J.; O\textquoterightBrien, T.; Looper, M.;

YEAR: 2018     DOI: 10.1029/2018GL080291

drift resonance; particle detector; Pc5; Radiation belts; ULF wave; Van Allen Probes; Wave-particle interaction

Eigenmodes of the transverse Alfv\ enic resonator at the plasmapause: a Van Allen Probes case study

A Pc4 ULF wave was detected at spacecraft B of the Van Allen Probes at the plasmapause. A distinctive feature of this wave is the strong periodical modulation of the wave. It is assumed that this modulation is a beating of oscillations close in frequency: at least two harmonics with frequencies of 15.3 and 13.6 MHz are found. It is shown that these harmonics can be the eigenmodes of the transverse resonator at the local maximum of the Alfv\ en velocity. In addition, the observed wave was in a drift resonance with energetic 8 ...

Mager, Pavel; Mikhailova, Olga; Mager, Olga; Klimushkin, Dmitri;

YEAR: 2018     DOI: 10.1029/2018GL079596

Magnetosphere; Plasmapause; poloidal Alfven waves; transverse resonator; ULF waves; Van Allen Probes; Wave-particle interaction

Generation of lower L -shell dayside chorus by energetic electrons from the plasmasheet

Currently, the generation mechanism for the lower L-shell dayside chorus has still remained an open question. Here, we report two storm events: 06-07 March 2016 and 20-21 January 2016, when Van Allen Probes observed enhanced dayside chorus with lower and higher wave normal angles (the angles between the wave vector and the geomagnetic field) in the region of L = 3.5-6.3 and MLT = 5.6-13.5. Hot and energetic (\~ 1-100 keV) electrons displayed enhancements in fluxes and anisotropy when they were injected from the plasmasheet a ...

He, Yihua; Xiao, Fuliang; Su, Zhenpeng; Zheng, Huinan; Yang, Chang; Liu, Si; Zhou, Qinghua;

YEAR: 2018     DOI: 10.1029/2017JA024889

Dayside chorus generation; Radiation belt; Van Allen Probes; Wave-particle interaction

Storm-time evolution of outer radiation belt relativistic electrons by a nearly continuous distribution of chorus

During the 13-14 November 2012 storm, Van Allen Probe A simultaneously observed a 10-h period of enhanced chorus (including quasi-parallel and oblique propagation components) and relativistic electron fluxes over a broad range of L = 3-6 and MLT=2 - 10 within a complete orbit cycle. By adopting a Gaussian fit to the observed wave spectra, we obtain the wave parameters and calculate the bounce-averaged diffusion coefficients. We solve the Fokker-Planck diffusion equation to simulate flux evolutions of relativistic (1.8-4.2 Me ...

Yang, Chang; Xiao, Fuliang; He, Yihua; Liu, Si; Zhou, Qinghua; Guo, Mingyue; Zhao, Wanli;

YEAR: 2018     DOI: 10.1002/2017GL075894

energetic electron; Geomagnetic storm; outer radiation belt; Van Allen Probes; Wave-particle interaction; whistler-mode chorus wave

Prompt Disappearance and Emergence of Radiation Belt Magnetosonic Waves Induced by Solar Wind Dynamic Pressure Variations

Magnetosonic waves are highly oblique whistler mode emissions transferring energy from the ring current protons to the radiation belt electrons in the inner magnetosphere. Here we present the first report of prompt disappearance and emergence of magnetosonic waves induced by the solar wind dynamic pressure variations. The solar wind dynamic pressure reduction caused the magnetosphere expansion, adiabatically decelerated the ring current protons for the Bernstein mode instability, and produced the prompt disappearance of magn ...

Liu, Nigang; Su, Zhenpeng; Zheng, Huinan; Wang, Yuming; Wang, Shui;

YEAR: 2018     DOI: 10.1002/2017GL076382

magnetosonic waves; Radiation belt; ring current; solar wind dynamic pressure; Van Allen Probes; Wave-particle interaction

2017

The Radiation Belt Electron Scattering by Magnetosonic Wave: Dependence on Key Parameters

Magnetosonic (MS) waves have been found capable of creating radiation belt electron butterfly distributions in the inner magnetosphere. To investigate the physical nature of the interactions between radiation belt electrons and MS waves, and to explore a preferential condition for MS waves to scatter electrons efficiently, we performed a comprehensive parametric study of MS wave-electron interactions using test particle simulations. The diffusion coefficients simulated by varying the MS wave frequency show that the scatterin ...

Lei, Mingda; Xie, Lun; Li, Jinxing; Pu, Zuyin; Fu, Suiyan; Ni, Binbin; Hua, Man; Chen, Lunjin; Li, Wen;

YEAR: 2017     DOI: 10.1002/2016JA023801

magnetosonic wave; parametric study; Radiation belt; Van Allen Probes; Wave-particle interaction

Shock-induced disappearance and subsequent recovery of plasmaspheric hiss: Coordinated observations of RBSP, THEMIS and POES satellites

Plasmaspheric hiss is an extremely low frequency whistler-mode emission contributing significantly to the loss of radiation belt electrons. There are two main competing mechanisms for the generation of plasmaspheric hiss: excitation by local instability in the outer plasmasphere and origination from chorus outside the plasmasphere. Here, on the basis of the analysis of an event of shock-induced disappearance and subsequent recovery of plasmaspheric hiss observed by RBSP, THEMIS and POES missions, we attempt to identify its d ...

Liu, Nigang; Su, Zhenpeng; Gao, Zhonglei; Reeves, G.; Zheng, Huinan; Wang, Yuming; Wang, Shui;

YEAR: 2017     DOI: 10.1002/2017JA024470

Chorus; interplanetary shock; Plasmaspheric Hiss; Radiation belt; substorm injection; Van Allen Probes; Wave-particle interaction

Rapid loss of radiation belt relativistic electrons by EMIC waves

How relativistic electrons are lost is an important question surrounding the complex dynamics of the Earth\textquoterights outer radiation belt. Radial loss to the magnetopause and local loss to the atmosphere are two main competing paradigms. Here, on the basis of the analysis of a radiation belt storm event on 27 February 2014, we present new evidence for the EMIC wave-driven local precipitation loss of relativistic electrons in the heart of the outer radiation belt. During the main phase of this storm, the radial profile ...

Su, Zhenpeng; Gao, Zhonglei; Zheng, Huinan; Wang, Yuming; Wang, Shui; Spence, H.; Reeves, G.; Baker, D.; Wygant, J.;

YEAR: 2017     DOI: 10.1002/2017JA024169

electron loss; EMIC waves; pitch angle scattering; radial diffusion; Radiation belts; Van Allen Probes; Wave-particle interaction

CIMI simulations with newly developed multi-parameter chorus and plasmaspheric hiss wave models

Numerical simulation studies of the Earth\textquoterights radiation belts are important to understand the acceleration and loss of energetic electrons. The Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model considers the effects of the ring current and plasmasphere on the radiation belts to obtain plausible results. The CIMI model incorporates pitch angle, energy, and cross diffusion of electrons, due to chorus and plasmaspheric hiss waves. These parameters are calculated using statistical wave distribution models of ...

Aryan, Homayon; Sibeck, David; Bin Kang, Suk-; Balikhin, Michael; Fok, Mei-Ching; Agapitov, Oleksiy; Komar, Colin; Kanekal, Shrikanth; Nagai, Tsugunobu;

YEAR: 2017     DOI: 10.1002/2017JA024159

Chorus and plasmaspheric hiss wave models; CIMI numerical simulations; Geomagnetic storm events; Radiation belt electron flux enhancements; Van Allen Probes; VLF waves; Wave-particle interaction

Direct observation of generation and propagation of magnetosonic waves following substorm injection

Magnetosonic whistler mode waves play an important role in the radiation belt electron dynamics. Previous theory has suggested that these waves are excited by the ring distributions of hot protons and can propagate radially and azimuthally over a broad spatial range. However, because of the challenging requirements on satellite locations and data-processing techniques, this theory was difficult to validate directly. Here we present some experimental tests of the theory on the basis of Van Allen Probes observations of magneto ...

Su, Zhenpeng; Wang, Geng; Liu, Nigang; Zheng, Huinan; Wang, Yuming; Wang, Shui;

YEAR: 2017     DOI: 10.1002/2017GL074362

Bernstein mode instability; magnetosonic waves; Radiation belt; rising tone; substorm injection; Van Allen Probes; Wave-particle interaction

Relativistic electron dynamics produced by azimuthally localized poloidal mode ULF waves: Boomerang-shaped pitch angle evolutions

We present an analysis of \textquotedblleftboomerang-shaped\textquotedblright pitch angle evolutions of outer radiation belt relativistic electrons observed by the Van Allen Probes after the passage of an interplanetary shock on June 7th, 2014. The flux at different pitch angles is modulated by Pc5 waves, with equatorially mirroring electrons reaching the satellite first. For 90o pitch angle electrons, the phase change of the flux modulations across energy exceeds 180o, and increasingly tilts with time. Using estimates of th ...

Hao, Y.; Zong, Q.-G.; Zhou, X.-Z.; Rankin, R.; Chen, X.; Liu, Y.; . Y. Fu, S; Spence, H.; Blake, J.; Reeves, G.;

YEAR: 2017     DOI: 10.1002/2017GL074006

drift resonance; interplanetary shock; localized waves; Radiation belts; ULF waves; Van Allen Probes; Wave-particle interaction

Generation of lower and upper bands of electrostatic electron cyclotron harmonic waves in the Van Allen radiation belts

Electrostatic electron cyclotron harmonic (ECH) waves generated by the electron loss cone distribution can produce efficient scattering loss of plasma sheet electrons, which has a significant effect on the dynamics in the outer magnetosphere. Here we report two ECH emission events around the same location L≈ 5.7\textendash5.8, MLT ≈ 12 from Van Allen Probes on 11 February (event A) and 9 January 2014 (event B), respectively. The spectrum of ECH waves was centered at the lower half of the harmonic bands during event A, bu ...

Zhou, Qinghua; Xiao, Fuliang; Yang, Chang; Liu, Si; He, Yihua; Baker, D.; Spence, H.; Reeves, G.; Funsten, H.;

YEAR: 2017     DOI: 10.1002/2017GL073051

ECH waves; RBSP results; Van Allen Probes; Wave-particle interaction

Generation of extremely low frequency chorus in Van Allen radiation belts

Recent studies have shown that chorus can efficiently accelerate the outer radiation belt electrons to relativistic energies. Chorus, previously often observed above 0.1 equatorial electron gyrofrequency fce, was generated by energetic electrons originating from Earth\textquoterights plasma sheet. Chorus below 0.1 fce has seldom been reported until the recent data from Van Allen Probes, but its origin has not been revealed so far. Because electron resonant energy can approach the relativistic level at extremely low frequency ...

Xiao, Fuliang; Liu, Si; Tao, Xin; Su, Zhenpeng; Zhou, Qinghua; Yang, Chang; He, Zhaoguo; He, Yihua; Gao, Zhonglei; Baker, D.; Spence, H.; Reeves, G.; Funsten, H.; Blake, J.;

YEAR: 2017     DOI: 10.1002/2016JA023561

ELF chorus waves; RBSP results; relativistic distribution; Van Allen Probes; Wave-particle interaction

A positive correlation between energetic electron butterfly distributions and magnetosonic waves in the radiation belt slot region

Energetic (hundreds of keV) electrons in the radiation belt slot region have been found to exhibit the butterfly pitch angle distributions. Resonant interactions with magnetosonic and whistler-mode waves are two potential mechanisms for the formation of these peculiar distributions. Here we perform a statistical study of energetic electron pitch angle distribution characteristics measured by Van Allen Probes in the slot region during a three-year period from May 2013 to May 2016. Our results show that electron butterfly dist ...

Yang, Chang; Su, Zhenpeng; Xiao, Fuliang; Zheng, Huinan; Wang, Yuming; Wang, Shui; Spence, H.; Reeves, G.; Baker, D.; Blake, J.; Funsten, H.;

YEAR: 2017     DOI: 10.1002/2017GL073116

butterfly distributions; Electron acceleration; Landau resonance; magnetosonic wave; Radiation belt; Van Allen Probes; Wave-particle interaction

2016

Statistical distribution of EMIC wave spectra: Observations from Van Allen Probes

It has been known that electromagnetic ion cyclotron (EMIC) waves can precipitate ultrarelativistic electrons through cyclotron resonant scattering. However, the overall effectiveness of this mechanism has yet to be quantified, because it is difficult to obtain the global distribution of EMIC waves that usually exhibit limited spatial presence. We construct a statistical distribution of EMIC wave frequency spectra and their intensities based on Van Allen Probes measurements from September 2012 to December 2015. Our results s ...

Zhang, X.-J.; Li, W.; Thorne, R.; Angelopoulos, V.; Bortnik, J.; Kletzing, C.; Kurth, W.; Hospodarsky, G.;

YEAR: 2016     DOI: 10.1002/2016GL071158

EMIC waves; magnetic storm; outer radiation belt; relativistic electron loss; Van Allen Probes; Wave-particle interaction

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;

YEAR: 2016     DOI: 10.1002/2016JA023087

electron loss; energetic electron; Plasmaspheric Hiss; Slot region; Van Allen Probes; Wave-particle interaction

Observation of chorus waves by the Van Allen Probes: Dependence on solar wind parameters and scale size

Highly energetic electrons in the Earth\textquoterights Van Allen radiation belts can cause serious damage to spacecraft electronic systems and affect the atmospheric composition if they precipitate into the upper atmosphere. Whistler mode chorus waves have attracted significant attention in recent decades for their crucial role in the acceleration and loss of energetic electrons that ultimately change the dynamics of the radiation belts. The distribution of these waves in the inner magnetosphere is commonly presented as a f ...

Aryan, Homayon; Sibeck, David; Balikhin, Michael; Agapitov, Oleksiy; Kletzing, Craig;

YEAR: 2016     DOI: 10.1002/jgra.v121.810.1002/2016JA022775

distribution of chorus wave intensities in the inner magnetosphere; inner magnetosphere; Radiation belts; scale size of chorus wave packets; Van Allen Probes; Wave-particle interaction

Direct evidence for EMIC wave scattering of relativistic electrons in space

Electromagnetic ion cyclotron (EMIC) waves have been proposed to cause efficient losses of highly relativistic (>1 MeV) electrons via gyroresonant interactions. Simultaneous observations of EMIC waves and equatorial electron pitch angle distributions, which can be used to directly quantify the EMIC wave scattering effect, are still very limited, however. In the present study, we evaluate the effect of EMIC waves on pitch angle scattering of ultrarelativistic (>1 MeV) electrons during the main phase of a geomagnetic storm, wh ...

Zhang, X.-J.; Li, W.; Ma, Q.; Thorne, R.; Angelopoulos, V.; Bortnik, J.; Chen, L.; Kletzing, C.; Kurth, W.; Hospodarsky, G.; Baker, D.; Reeves, G.; Spence, H.; Blake, J.; Fennell, J.;

YEAR: 2016     DOI: 10.1002/2016JA022521

electron precipitation; EMIC waves; equatorial pitch angle distribution; Fokker-Planck equation; relativistic electron loss; Van Allen Probes; Wave-particle interaction

Nonstorm time dropout of radiation belt electron fluxes on 24 September 2013

Radiation belt electron flux dropouts during the main phase of geomagnetic storms have received increasing attention in recent years. Here we focus on a rarely reported nonstorm time dropout event observed by Van Allen Probes on 24 September 2013. Within several hours, the radiation belt electron fluxes exhibited a significant (up to 2 orders of magnitude) depletion over a wide range of radial distances (L > 4.5), energies (\~500 keV to several MeV) and equatorial pitch angles (0\textdegree<=αe<=180\textdegree). STEERB simu ...

Su, Zhenpeng; Gao, Zhonglei; Zhu, Hui; Li, Wen; Zheng, Huinan; Wang, Yuming; Wang, Shui; Spence, H.; Reeves, G.; Baker, D.; Blake, J.; Funsten, H.; Wygant, J.;

YEAR: 2016     DOI: 10.1002/2016JA022546

EMIC; numerical modeling; Plasmaspheric Hiss; precipitation loss; radiation belt dropout; Van Allen Probes; Wave-particle interaction

Oblique Whistler-Mode Waves in the Earth\textquoterights Inner Magnetosphere: Energy Distribution, Origins, and Role in Radiation Belt Dynamics

In this paper we review recent spacecraft observations of oblique whistler-mode waves in the Earth\textquoterights inner magnetosphere as well as the various consequences of the presence of such waves for electron scattering and acceleration. In particular, we survey the statistics of occurrences and intensity of oblique chorus waves in the region of the outer radiation belt, comprised between the plasmapause and geostationary orbit, and discuss how their actual distribution may be explained by a combination of linear and no ...

Artemyev, Anton; Agapitov, Oleksiy; Mourenas, Didier; Krasnoselskikh, Vladimir; Shastun, Vitalii; Mozer, Forrest;

YEAR: 2016     DOI: 10.1007/s11214-016-0252-5

Earth radiation belts; Van Allen Probes; Wave-particle interaction; Whistler waves

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

Ultralow frequency (ULF) electromagnetic waves in Earth\textquoterights magnetosphere can accelerate charged particles via a process called drift resonance. In the conventional drift-resonance theory, a default assumption is that the wave growth rate is time-independent, positive, and extremely small. However, this is not the case for ULF waves in the real magnetosphere. The ULF waves must have experienced an earlier growth stage when their energy was taken from external and/or internal sources, and as time proceeds the wave ...

Zhou, Xu-Zhi; Wang, Zi-Han; Zong, Qiu-Gang; Rankin, Robert; Kivelson, Margaret; Chen, Xing-Ran; Blake, Bernard; Wygant, John; Kletzing, Craig;

YEAR: 2016     DOI: 10.1002/2016JA022447

drift resonance; Radiation belt; ULF waves; Van Allen Probes; wave growth and damping; Wave-particle interaction

2015

Wave-particle interactions in the outer radiation belts

Data from the Van Allen Probes have provided the first extensive evidence of non-linear (as opposed to quasi-linear) wave-particle interactions in space, with the associated rapid (fraction of a bounce period) electron acceleration, to hundreds of keV by Landau resonance, in the parallel electric fields of time domain structures (TDS) and very oblique chorus waves. The experimental evidence, simulations, and theories of these processes are discussed.

Agapitov, O.~V.; Mozer, F.~S.; Artemyev, A.~V.; Mourenas, D.; Krasnoselskikh, V.~V.;

YEAR: 2015     DOI:

plasma waves and instabilities; Radiation belts; Van Allen Probes; Wave-particle interaction

Electron distribution function formation in regions of diffuse aurora

The precipitation of high-energy magnetospheric electrons (E \~ 600 eV\textendash10 KeV) in the diffuse aurora contributes significant energy flux into the Earth\textquoterights ionosphere. To fully understand the formation of this flux at the upper ionospheric boundary, \~700\textendash800 km, it is important to consider the coupled ionosphere-magnetosphere system. In the diffuse aurora, precipitating electrons initially injected from the plasma sheet via wave-particle interaction processes degrade in the atmosphere toward ...

Khazanov, G.; Tripathi, A.; Sibeck, D.; Himwich, E.; Glocer, A.; Singhal, R.;

YEAR: 2015     DOI: 10.1002/2015JA021728

diffuse aurora; electron distribution; Wave-particle interaction

Penetration of magnetosonic waves into the plasmasphere observed by the Van Allen Probes

During the small storm on 14\textendash15 April 2014, Van Allen Probe A measured a continuously distinct proton ring distribution and enhanced magnetosonic (MS) waves along its orbit outside the plasmapause. Inside the plasmasphere, strong MS waves were still present but the distinct proton ring distribution was falling steeply with distance. We adopt a sum of subtracted bi-Maxwellian components to model the observed proton ring distribution and simulate the wave trajectory and growth. MS waves at first propagate toward lowe ...

Xiao, Fuliang; Zhou, Qinghua; He, Yihua; Yang, Chang; Liu, Si; Baker, D.; Spence, H.; Reeves, G.; Funsten, H.; Blake, J.;

YEAR: 2015     DOI: 10.1002/2015GL065745

Geomagnetic storms; magnetosonic waves; proton ring distribution; Radiation belts; Van Allen Probe results; Van Allen Probes; Wave-particle interaction

Imprints of impulse-excited hydromagnetic waves on electrons in the Van Allen radiation belts

Ultralow frequency electromagnetic oscillations, interpreted as standing hydromagnetic waves in the magnetosphere, are a major energy source that accelerates electrons to relativistic energies in the Van Allen radiation belt. Electrons can rapidly gain energy from the waves when they resonate via a process called drift resonance, which is observationally characterized by energy-dependent phase differences between electron flux and electromagnetic oscillations. Such dependence has been recently observed and interpreted as spa ...

Zhou, Xu-Zhi; Wang, Zi-Han; Zong, Qiu-Gang; Claudepierre, Seth; Mann, Ian; Kivelson, Margaret; Angelopoulos, Vassilis; Hao, Yi-Xin; Wang, Yong-Fu; Pu, Zu-Yin;

YEAR: 2015     DOI: 10.1002/grl.v42.1510.1002/2015GL064988

drift resonance; Radiation belt; ULF waves; Van Allen Probes; wave growth; Wave-particle interaction

Van Allen Probes observation and modeling of chorus excitation and propagation during weak geomagnetic activities

We report correlated data on nightside chorus waves and energetic electrons during two small storm periods: 1 November 2012 (Dst≈-45) and 14 January 2013 (Dst≈-18). The Van Allen Probes simultaneously observed strong chorus waves at locations L = 5.8 - 6.3, with a lower frequency band 0.1 - 0.5fce and a peak spectral density \~[10-4 nT2/Hz. In the same period, the fluxes and anisotropy of energetic (\~ 10-300 keV) electrons were greatly enhanced in the interval of large negative interplanetary magnetic field Bz. Using a ...

He, Yihua; Xiao, Fuliang; Zhou, Qinghua; Yang, Chang; Liu, Si; Baker, D.; Kletzing, C.; Kurth, W.; Hospodarsky, G.; Spence, H.; Reeves, G.; Funsten, H.; Blake, J.;

YEAR: 2015     DOI: 10.1002/2015JA021376

chorus wave excitation; energetic electrons; Geomagnetic storm; Van Allen Probes; Van Allen probes results; Wave-particle interaction

A computational and theoretical investigation of nonlinear wave-particle interactions in oblique whistlers

Most previous work on nonlinear wave-particle interactions between energetic electrons and VLF waves in the Earth\textquoterights magnetosphere has assumed parallel propagation, the underlying mechanism being nonlinear trapping of cyclotron resonant electrons in a parabolic magnetic field inhomogeneity. Here nonlinear wave-particle interaction in oblique whistlers in the Earth\textquoterights magnetosphere is investigated. The study is nonself-consistent and assumes an arbitrarily chosen wave field. We employ a \textquotedbl ...

Nunn, David; Omura, Yoshiharu;

YEAR: 2015     DOI: 10.1002/2014JA020898

Chorus; nonlinear process; oblique propagation; simulation; Wave-particle interaction; whistler

2014

Quantifying the relative contributions of substorm injections and chorus waves to the rapid outward extension of electron radiation belt

We study the rapid outward extension of the electron radiation belt on a timescale of several hours during three events observed by RBSP and THEMIS satellites, and particularly quantify the contributions of substorm injections and chorus waves to the electron flux enhancement near the outer boundary of radiation belt. A comprehensive analysis including both observations and simulations is performed for the first event on 26 May 2013. The outer boundary of electron radiation belt moved from L = 5.5 to L > 6.07 over about 6 ho ...

Su, Zhenpeng; Zhu, Hui; Xiao, Fuliang; Zheng, Huinan; Wang, Yuming; Zong, Q.-G.; He, Zhaoguo; Shen, Chao; Zhang, Min; Wang, Shui; Kletzing, C.; Kurth, W.; Hospodarsky, G.; Spence, H.; Reeves, G.; Funsten, H.; Blake, J.; Baker, D.;

YEAR: 2014     DOI: 10.1002/2014JA020709

Chorus wave; Electron acceleration; Radiation belt; substorm injection; Van Allen Probes; Wave-particle interaction

Characteristics of pitch angle distributions of 100 s keV electrons in the slot region and inner radiation belt

The pitch angle distribution (PAD) of energetic electrons in the slot region and inner radiation belt received little attention in the past decades due to the lack of quality measurements. Using the state-of-art pitch-angle-resolved data from the Magnetic Electron Ion Spectrometer (MagEIS) instrument onboard the Van Allen Probes, a detailed analysis of 100 s keV electron PADs below L = 4 is performed, in which the PADs is categorized into three types: normal (flux peaking at 90o), cap (exceedingly peaking narrowly around 90o ...

Zhao, H.; Li, X.; Blake, J.; Fennell, J.; Claudepierre, S.; Baker, D.; Jaynes, A.; Malaspina, D.;

YEAR: 2014     DOI: 10.1002/2014JA020386

energetic electrons; Inner radiation belt; Pitch angle distribution; plasmasphere; Slot region; Van Allen Probes; Wave-particle interaction

Excitation of nightside magnetosonic waves observed by Van Allen Probes

During the recovery phase of the geomagnetic storm on 30-31 March 2013, Van Allen Probe A detected enhanced magnetosonic (MS) waves in a broad range of L =1.8-4.7 and MLT =17-22 h, with a frequency range ~10-100 Hz. In the meanwhile, distinct proton ring distributions with peaks at energies of ~10 keV, were also observed in L =3.2-4.6 and L =5.0-5.6. Using a subtracted bi-Maxwellian distribution to model the observed proton ring distribution, we perform three dimensional ray tracing to investigate the instability, propagatio ...

Zhou, Qinghua; Xiao, Fuliang; Yang, Chang; Liu, Si; Kletzing, C.; Kurth, W.; Hospodarsky, G.; Spence, H.; Reeves, G.; Funsten, H.; Blake, J.; Baker, D.; Wygant, J.;

YEAR: 2014     DOI: 10.1002/2014JA020481

magnetosonic wave; RBSP results; Van Allen Probes; Wave-particle interaction

Fast transport of resonant electrons in phase space due to nonlinear trapping by whistler waves

We present an analytical, simplified formulation accounting for the fast transport of relativistic electrons in phase space due to wave-particle resonant interactions in the inhomogeneous magnetic field of Earth\textquoterights radiation belts. We show that the usual description of the evolution of the particle velocity distribution based on the Fokker-Planck equation can be modified to incorporate nonlinear processes of wave-particle interaction, including particle trapping. Such a modification consists in one additional op ...

Artemyev, A.; Vasiliev, A.; Mourenas, D.; Agapitov, O.; Krasnoselskikh, V.; Boscher, D.; Rolland, G.;

YEAR: 2014     DOI: 10.1002/grl.v41.1610.1002/2014GL061380

particle trapping; Radiation belts; Wave-particle interaction

Thermal electron acceleration by localized bursts of electric field in the radiation belts

In this paper we investigate the resonant interaction of thermal ~10-100 eV electrons with a burst of electrostatic field that results in electron acceleration to kilovolt energies. This single burst contains a large parallel electric field of one sign and a much smaller, longer lasting parallel field of the opposite sign. The Van Allen Probe spacecraft often observes clusters of spatially localized bursts in the Earth\textquoterights outer radiation belts. These structures propagate mostly away from thegeomagnetic equator a ...

Artemyev, A.; Agapitov, O.; Mozer, F.; Krasnoselskikh, V.;

YEAR: 2014     DOI: 10.1002/2014GL061248

Radiation belts; thermal electrons; Van Allen Probes; Wave-particle interaction

Inner belt and slot region electron lifetimes and energization rates based on AKEBONO statistics of whistler waves

Global statistics of the amplitude distributions of hiss, lightning-generated, and other whistler mode waves from terrestrial VLF transmitters have been obtained from the EXOS-D (Akebono) satellite in the Earth\textquoterights plasmasphere and fitted as functions of L and latitude for two geomagnetic activity ranges (Kp<3 and Kp>3). In particular, the present study focuses on the inner zone L∈[1.4,2] where reliable in situ measurements were lacking. Such statistics are critically needed for an accurate assessment of the ro ...

Agapitov, O.; Artemyev, A.; Mourenas, D.; Kasahara, Y.; Krasnoselskikh, V.;

YEAR: 2014     DOI: 10.1002/jgra.v119.410.1002/2014JA019886

Inner radiation belt; Van Allen Probes; Wave-particle interaction



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