Bibliography



Found 12 entries in the Bibliography.


Showing entries from 1 through 12


2020

Unraveling the Formation Mechanism for the Bursts of Electron Butterfly Distributions: Test Particle and Quasilinear Simulations

Energetic electron dynamics is highly affected by plasma waves through quasilinear and/or nonlinear interactions in the Earth s inner magnetosphere. In this letter, we provide physical explanations for a previously reported intriguing event from the Van Allen Probes observations, where bursts of electron butterfly distributions at tens of keV exhibit remarkable correlations with chorus waves. Both test particle and quasilinear simulations are used to reveal the formation mechanism for the bursts of electron butterfly distrib ...

Gan, L.; Li, W.; Ma, Q.; Artemyev, A.; Albert, J.;

YEAR: 2020     DOI: https://doi.org/10.1029/2020GL090749

butterfly distribution; chorus waves; Electron acceleration; Radiation belts; nonlinear interaction; Van Allen Probes

The Impenetrable Barrier: Suppression of Chorus Wave Growth by VLF Transmitters

Rapid radiation belt recovery following storm time depletion involves local acceleration of multi-MeV electrons in nonlinear interactions with VLF chorus waves. Previous studies of an apparent impenetrable barrier at L ~ 2.8 focused on diffusion and precipitation loss mechanisms for an explanation of the sharp reduction of multi-MeV electron fluxes earthward of L ~ 3. Van Allen Probes observations for cases when the plasmasphere is contracted earthward of L ~ 3 indicate that strong coherent signals from VLF transmitter ...

Foster, John; Erickson, Philip; Omura, Yoshiharu; Baker, Daniel;

YEAR: 2020     DOI: https://doi.org/10.1029/2020JA027913

Radiation belt; Plasmapause; VLF transmitters; wave-particle interactions; Electron acceleration; nonlinear VLF chorus; Van Allen Probes

2019

Nonlinear Electron Interaction With Intense Chorus Waves: Statistics of Occurrence Rates

A comprehensive statistical analysis on 8 years of lower-band chorus wave packets measured by the Van Allen Probes and THEMIS spacecraft is performed to examine whether, when, and where these waves are above the theoretical threshold for nonlinear resonant wave-particle interaction. We find that \~5\textendash30\% of all chorus waves interact nonlinearly with \~30- to 300-keV electrons possessing equatorial pitch angles of >40\textdegree in the outer radiation belt, especially during disturbed (AE>500 nT) periods with energe ...

Zhang, X.-J.; Mourenas, D.; Artemyev, A.; Angelopoulos, V.; Bortnik, J.; Thorne, R.; Kurth, W.; Kletzing, C.; Hospodarsky, G.;

YEAR: 2019     DOI: 10.1029/2019GL083833

chorus waves; Electron acceleration; nonlinear wave particle interaction; THEMIS; Van Allen Probes; wave packet size

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.; . Y. Li, L; Cui, J.; Cao, J.; Wang, J.;

YEAR: 2019     DOI: 10.1029/2018JA026328

bounce resonance; Electron acceleration; Landau resonance; magnetosonic waves; transit-time scattering; Van Allen Probes

2018

Nonlinear Electrostatic Steepening of Whistler Waves: The Guiding Factors and Dynamics in Inhomogeneous Systems

Whistler mode chorus waves are particularly important in outer radiation belt dynamics due to their key role in controlling the acceleration and scattering of electrons over a very wide energy range. The efficiency of wave-particle resonant interactions is defined by whistler wave properties which have been described by the approximation of plane linear waves propagating through the cold plasma of the inner magnetosphere. However, recent observations of extremely high-amplitude whistlers suggest the importance of nonlinear w ...

Agapitov, O.; Drake, J.; Vasko, I.; Mozer, F.; Artemyev, A.; Krasnoselskikh, V.; Angelopoulos, V.; Wygant, J.; Reeves, G.;

YEAR: 2018     DOI: 10.1002/2017GL076957

Electron acceleration; electron acoustic waves; induced scattering; nonlinear wave-particle interactions; Van Allen Probes; wave steepening; Whistler waves

Space Weather Operation at KASI with Van Allen Probes Beacon Signals

The Van Allen Probes (VAPs) are the only modern NASA spacecraft broadcasting real-time data on the Earth\textquoterights radiation belts for space weather operations. Since 2012, the Korea Astronomy and Space Science Institute (KASI) has contributed to the receipt of this data via a 7-m satellite tracking antenna and used these data for space weather operations. An approximately 15-min period is required from measurement to acquisition of Level-1 data. In this paper, we demonstrate the use of VAP data for monitoring space we ...

Lee, Jongkil; Kim, Kyung-Chan; Romeo, Giuseppe; Ukhorskiy, Sasha; Sibeck, David; Kessel, Ramona; Mauk, Barry; Giles, Barbara; Gu, Bon-Jun; Lee, Hyesook; Park, Young-Deuk; Lee, Jaejin;

YEAR: 2018     DOI: 10.1002/2017SW001726

Electron acceleration; Radiation belt; Relativistic electron; Space weather; Van Allen Probes

2017

Acceleration of radiation belt electrons and the role of the average interplanetary magnetic field B z component in high speed streams

In this study we examine the recovery of relativistic radiation belt electrons on November 15-16, 2014, after a previous reduction in the electron flux resulting from the passage of a Corotating Interaction Region (CIR). Following the CIR, there was a period of high-speed streams characterized by large, nonlinear fluctuations in the interplanetary magnetic field (IMF) components. However, the outer radiation belt electron flux remained at a low level for several days before it increased in two major steps. The first increase ...

Souza, V.; Lopez, R.; Jauer, P.; Sibeck, D.; Pham, K.; Silva, L.; Marchezi, J.; Alves, L.; Koga, D.; Medeiros, C.; Rockenbach, M.; Gonzalez, W.;

YEAR: 2017     DOI: 10.1002/2017JA024187

Electron acceleration; High-speed solar wind streams; IMF Bz fluctuations; Outer Van Allen belt; Van Allen Probes

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

Electron holes in the outer radiation belt: Characteristics and their role in electron energization

Van Allen Probes have detected electron holes (EHs) around injection fronts in the outer radiation belt. Presumably generated near equator, EHs propagate to higher latitudes potentially resulting in energization of electrons trapped within EHs. This process has been recently shown to provide electrons with energies up to several tens of keV and requires EH propagation up to rather high latitudes. We have analyzed more than 100 EHs observed around a particular injection to determine their kinetic structure and potential energ ...

. Y. Vasko, I; Agapitov, O.; Mozer, F.; Artemyev, A.; Drake, J.; Kuzichev, I.;

YEAR: 2016     DOI: 10.1002/2016JA023083

Electron acceleration; electron holes; injection; Radiation belt; solitary waves; Van Allen Probes

Radiation belt electron acceleration during the 17 March 2015 geomagnetic storm: Observations and simulations

Various physical processes are known to cause acceleration, loss, and transport of energetic electrons in the Earth\textquoterights radiation belts, but their quantitative roles in different time and space need further investigation. During the largest storm over the past decade (17 March 2015), relativistic electrons experienced fairly rapid acceleration up to ~7 MeV within 2 days after an initial substantial dropout, as observed by Van Allen Probes. In the present paper, we evaluate the relative roles of various physical p ...

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

YEAR: 2016     DOI: 10.1002/jgra.v121.610.1002/2016JA022400

chorus-driven local acceleration; Electron acceleration; radial diffusion; Van Allen Probes

2015

Solar wind conditions leading to efficient radiation belt electron acceleration: A superposed epoch analysis

Determining preferential solar wind conditions leading to efficient radiation belt electron acceleration is crucial for predicting radiation belt electron dynamics. Using Van Allen Probes electron observations (>1 MeV) from 2012 to 2015, we identify a number of efficient and inefficient acceleration events separately to perform a superposed epoch analysis of the corresponding solar wind parameters and geomagnetic indices. By directly comparing efficient and inefficient acceleration events, we clearly show that prolonged sout ...

Li, W.; Thorne, R.; Bortnik, J.; Baker, D.; Reeves, G.; Kanekal, S.; Spence, H.; Green, J.;

YEAR: 2015     DOI: 10.1002/2015GL065342

Chorus wave; Electron acceleration; solar wind conditions; Van Allen Probes

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



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