Bibliography



Found 11 entries in the Bibliography.


Showing entries from 1 through 11


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

2018

What Causes Radiation Belt Enhancements: A Survey of the Van Allen Probes Era

We survey radiation belt enhancement events during the Van Allen Probes era to determine what mechanism is the dominant cause of enhancements and where it is most effective. Two primary mechanisms have been proposed: (1) betatron/Fermi acceleration due to the Earthward radial transport of electrons which produces monotonic gradients in phase space density (PSD) and (2) \textquotedblleftlocal acceleration" due to gyro/Landau resonant interaction with electromagnetic waves which produces radially localized, growing peaks in PS ...

Boyd, A.J.; Turner, D.L.; Reeves, G.D.; Spence, H.E.; Baker, D.N.; Blake, J.B.;

YEAR: 2018     DOI: 10.1029/2018GL077699

Local Acceleration; Phase space density; Radiation belt; THEMIS; Van Allen Probes

Quantifying Extremely Rapid Flux Enhancements of Radiation Belt Relativistic Electrons Associated With Radial Diffusion

Previous studies have revealed a typical picture that seed electrons are transported inward under the drive of radial diffusion and then accelerated via chorus to relativistic energies. Here we show a potentially different process during the 2\textendash3 October 2013 storm when Van Allen Probes observed extremely rapid (by about 50 times in 2 h) flux enhancements of relativistic (1.8\textendash3.4 MeV) electrons but without distinct chorus at lower L-shells. Meanwhile, Time History of Events and Macroscale Interactions duri ...

Liu, Si; Yan, Qi; Yang, Chang; Zhou, Qinghua; He, Zhaoguo; He, Yihua; Gao, Zhonglei; Xiao, Fuliang;

YEAR: 2018     DOI: 10.1002/grl.v45.310.1002/2017GL076513

chorus-driven acceleration; radial diffusion; Radiation belt; THEMIS; Van Allen Probes

2017

Cross-scale observations of the 2015 St. Patrick\textquoterights day storm: THEMIS, Van Allen Probes, and TWINS

We present cross-scale magnetospheric observations of the 17 March 2015 (St. Patrick\textquoterights Day) storm, by Time History of Events and Macroscale Interactions during Substorms (THEMIS), Van Allen Probes (Radiation Belt Storm Probes), and Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS), plus upstream ACE/Wind solar wind data. THEMIS crossed the bow shock or magnetopause 22 times and observed the magnetospheric compression that initiated the storm. Empirical models reproduce these boundary locations within 0. ...

Goldstein, J.; Angelopoulos, V.; De Pascuale, S.; Funsten, H.; Kurth, W.; LLera, K.; McComas, D.; Perez, J.; Reeves, G.; Spence, H.; Thaller, S.; Valek, P.; Wygant, J.;

YEAR: 2017     DOI: 10.1002/2016JA023173

Heliophysics System Observatory; Modeling; multimission; THEMIS; TWINS; Van Allen Probes

Cross-scale observations of the 2015 St. Patrick\textquoterights day storm: THEMIS, Van Allen Probes, and TWINS

We present cross-scale magnetospheric observations of the 17 March 2015 (St. Patrick\textquoterights Day) storm, by Time History of Events and Macroscale Interactions during Substorms (THEMIS), Van Allen Probes (Radiation Belt Storm Probes), and Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS), plus upstream ACE/Wind solar wind data. THEMIS crossed the bow shock or magnetopause 22 times and observed the magnetospheric compression that initiated the storm. Empirical models reproduce these boundary locations within 0. ...

Goldstein, J.; Angelopoulos, V.; De Pascuale, S.; Funsten, H.; Kurth, W.; LLera, K.; McComas, D.; Perez, J.; Reeves, G.; Spence, H.; Thaller, S.; Valek, P.; Wygant, J.;

YEAR: 2017     DOI: 10.1002/jgra.v122.110.1002/2016JA023173

Heliophysics System Observatory; Modeling; multimission; THEMIS; TWINS; Van Allen Probes

2015

Sub-packet structures in EMIC rising tone emissions observed by the THEMIS probes

We report sub-packet structures found in electromagnetic ion cyclotron (EMIC) rising tone emissions observed by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) probles. We investigate three typical cases in detail. The first case shows a continuous single rising tone with obvious four sub-packets, and the second case is characterized by a patchy emission with multiple sub-packets triggered in a broadband frequency. The third case looks like a smooth rising tone without any obvious sub-packet ...

Nakamura, Satoko; Omura, Yoshiharu; Shoji, Masafumi; e, Masahito; Summers, Danny; Angelopoulos, Vassilis;

YEAR: 2015     DOI: 10.1002/2014JA020764

EMIC wave; inner magnetosphere; The nonlinear wave growth; THEMIS

New model fit functions of the plasmapause location determined using THEMIS observations during the ascending phase of Solar Cycle 24

It is well known that the plasmapause is influenced by the solar wind and magnetospheric conditions. Empirical models of its location have been previously developed such as those by O\textquoterightBrien and Moldwin (2003) and Larsen et al. (2006). In this study, we identified the locations of the plasmapause using the plasma density data obtained from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites. We used the data for the period (2008\textendash2012) corresponding to the ascendi ...

Cho, Junghee; Lee, Dae-Young; Kim, Jin-Hee; Shin, Dae-Kyu; Kim, Kyung-Chan; Turner, Drew;

YEAR: 2015     DOI: 10.1002/2015JA021030

Plasmapause; THEMIS

Energetic electron injections deep into the inner magnetosphere associated with substorm activity

From a survey of the first nightside season of NASA\textquoterights Van Allen Probes mission (Dec/2012 \textendash Sep/2013), 47 energetic (10s to 100s of keV) electron injection events were found at L-shells <= 4, all of which are deeper than any previously reported substorm-related injections. Preliminary details from these events are presented, including how: all occurred shortly after dipolarization signatures and injections were observed at higher L-shells; the deepest observed injection was at L~2.5; and, surprisingly, ...

Turner, D.; Claudepierre, S.; Fennell, J.; O\textquoterightBrien, T.; Blake, J.; Lemon, C.; Gkioulidou, M.; Takahashi, K.; Reeves, G.; Thaller, S.; Breneman, A.; Wygant, J.; Li, W.; Runov, A.; Angelopoulos, V.;

YEAR: 2015     DOI: 10.1002/2015GL063225

energetic particle injections; inner magnetosphere; Radiation belts; substorms; THEMIS; Van Allen Probes

2014

Observations and modeling of EMIC wave properties in the presence of multiple ion species as function of magnetic local time

Electromagnetic ion cyclotron (EMIC) wave generation and propagation in Earth\textquoterights magnetosphere depend on readily measurable hot (a few to tens of keV) plasma sheet ions, elusive plasmaspheric or ionospheric cold (sub-eV to a few eV) ions, and partially heated warm ions (tens to hundreds of eV). Previous work has assumed all low-energy ions are cold and not considered possible effects of warm ions. Using measurements by multiple Time History of Events and Macroscale Interactions during Substorms spacecraft, we an ...

Lee, Justin; Angelopoulos, Vassilis;

YEAR: 2014     DOI: 10.1002/2014JA020469

EMIC waves; ion composition; ion cyclotron waves; low-energy ions; THEMIS; warm plasma effects

Statistical results describing the bandwidth and coherence coefficient of whistler mode waves using THEMIS waveform data

The bandwidths and coherence coefficients of lower band whistler mode waves are analyzed using Time History of Events and Macroscale Interactions during Substorms (THEMIS) waveform data for rising tones, falling tones, and hiss-like emissions separately. We also evaluate their dependences on the spatial location, electron density, the ratio of plasma frequency to local electron gyrofrequency (fpe/fce), and the wave amplitude. Our results show that the bandwidth normalized by the local electron gyrofrequency (fce) of rising a ...

Gao, X.; Li, W.; Thorne, R.; Bortnik, J.; Angelopoulos, V.; Lu, Q.; Tao, X.; Wang, S.;

YEAR: 2014     DOI: 10.1002/2014JA020158

bandwidth; coherence coefficient; nonlinear; quasi-linear; THEMIS; whistler mode waves

2013

Characteristic dimension of electromagnetic ion cyclotron wave activity in the magnetosphere

[1] In this paper, we estimate the size of coherent activity of electromagnetic ion cyclotron (EMIC) waves using the multi-spacecraft observations made during the Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission. We calculate the cross-correlations between EMIC wave powers measured by different THEMIS spacecraft, plot them over the separation distances between pairs of observing spacecraft, and determine the 1/e folding distance of the correlations as the characteristic dimension of the co ...

Lee, Jeongwoo; Min, Kyungguk; Kim, Kap-Sung;

YEAR: 2013     DOI: 10.1002/jgra.50242

EMIC wave powers; RBSP; THEMIS; Van Allen Probes



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