Found 115 entries in the Bibliography.

Showing entries from 101 through 115


Whistler Anisotropy Instabilities as the Source of Banded Chorus: Van Allen Probes Observations and Particle-in-Cell Simulations

Magnetospheric banded chorus is enhanced whistler waves with frequencies ωr < Ωe, where Ωe is the electron cyclotron frequency, and a characteristic spectral gap at ωr ≃ Ωe/2. This paper uses spacecraft observations and two-dimensional particle-in-cell (PIC) simulations in a magnetized, homogeneous, collisionless plasma to test the hypothesis that banded chorus is due to local linear growth of two branches of the whistler anisotropy instability excited by two distinct, anisotropic electron components of significantly ...

Fu, Xiangrong; Cowee, Misa; Friedel, Reinhard; Funsten, Herbert; Gary, Peter; Hospodarsky, George; Kletzing, Craig; Kurth, William; Larsen, Brian; Liu, Kaijun; MacDonald, Elizabeth; Min, Kyungguk; Reeves, Geoffrey; Skoug, Ruth; Winske, Dan;

YEAR: 2014     DOI: 10.1002/2014JA020364

Chorus; HOPE; particle-in-cell simulation; Van Allen Probes

Interactions of energetic electrons with ULF waves triggered by interplanetary shock: Van Allen Probes observations in the magnetotail

We present in situ observations of a shock-induced substorm-like event on 13 April 2013 observed by the newly launched Van Allen twin probes. Substorm-like electron injections with energy of 30\textendash500 keV were observed in the region from L\~5.2 to 5.5 immediately after the shock arrival (followed by energetic electron drift echoes). Meanwhile, the electron flux was clearly and strongly varying on the ULF wave time scale. It is found that both toroidal and poloidal mode ULF waves with a period of 150 s emerged followin ...

Hao, Y.; Zong, Q.-G.; Wang, Y.; Zhou, X.-Z.; Zhang, Hui; . Y. Fu, S; . Y. Pu, Z; Spence, H.; Blake, J.; Bonnell, J.; Wygant, J.; Kletzing, C.;

YEAR: 2014     DOI: 10.1002/2014JA020023

energetic particles; interplanetary shock; magnetotail ULF wave; poloidal and toroidal mode; Van Allen Probes; wave-particle interactions

Magnetospheric Multiscale Science Mission Profile and Operations

The Magnetospheric Multiscale (MMS) mission and operations are designed to provide the maximum reconnection science. The mission phases are chosen to investigate reconnection at the dayside magnetopause and in the magnetotail. At the dayside, the MMS orbits are chosen to maximize encounters with the magnetopause in regions where the probability of encountering the reconnection diffusion region is high. In the magnetotail, the orbits are chosen to maximize encounters with the neutral sheet, where reconnection is known to occu ...

Fuselier, S.; Lewis, W.; Schiff, C.; Ergun, R.; Burch, J.; Petrinec, S.; Trattner, K.;

YEAR: 2014     DOI: 10.1007/s11214-014-0087-x

Magnetic reconnection; Magnetospheric multiscale; Space mission design; Spacecraft orbits

Excitation of EMIC waves detected by the Van Allen Probes on 28 April 2013

We report the wave observations, associated plasma measurements, and linear theory testing of electromagnetic ion cyclotron (EMIC) wave events observed by the Van Allen Probes on 28 April 2013. The wave events are detected in their generation regions as three individual events in two consecutive orbits of Van Allen Probe-A, while the other spacecraft, B, does not detect any significant EMIC wave activity during this period. Three overlapping H+ populations are observed around the plasmapause when the waves are excited. The d ...

Zhang, J.-C.; Saikin, A.; Kistler, L.; Smith, C.; Spence, H.; Mouikis, C.; Torbert, R.; Larsen, B.; Reeves, G.; Skoug, R.; Funsten, H.; Kurth, W.; Kletzing, C.; Allen, R.; Jordanova, V.;

YEAR: 2014     DOI: 10.1002/2014GL060621

Van Allen Probes

Intense duskside lower band chorus waves observed by Van Allen Probes: Generation and potential acceleration effect on radiation belt electrons

Local acceleration driven by whistler mode chorus waves largely accounts for the enhancement of radiation belt relativistic electron fluxes, whose favored region is usually considered to be the plasmatrough with magnetic local time approximately from midnight through dawn to noon. On 2 October 2013, the Van Allen Probes recorded a rarely reported event of intense duskside lower band chorus waves (with power spectral density up to 10-3nT2/Hz) in the low-latitude region outside of L=5. Such chorus waves are found to be generat ...

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

YEAR: 2014     DOI: 10.1002/jgra.v119.610.1002/2014JA019919

Van Allen Probes

Chorus acceleration of radiation belt relativistic electrons during March 2013 geomagnetic storm

The recent launching of Van Allen probes provides an unprecedent opportunity to investigate variations of the radiation belt relativistic electrons. During the 17\textendash19 March 2013 storm, the Van Allen probes simultaneously detected strong chorus waves and substantial increases in fluxes of relativistic (2 - 4.5 MeV) electrons around L = 4.5. Chorus waves occurred within the lower band 0.1\textendash0.5fce (the electron equatorial gyrofrequency), with a peak spectral density \~10-4 nT2/Hz. Correspondingly, relativistic ...

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

YEAR: 2014     DOI: 10.1002/2014JA019822

Van Allen Probes

Van Allen Probes observations of direct wave-particle interactions

Quasiperiodic increases, or \textquotedblleftbursts,\textquotedblright of 17\textendash26 keV electron fluxes in conjunction with chorus wave bursts were observed following a plasma injection on 13 January 2013. The pitch angle distributions changed during the burst events, evolving from sinN(α) to distributions that formed maxima at α = 75\textendash80\textdegree, while fluxes at 90\textdegree and <60\textdegree remained nearly unchanged. The observations occurred outside of the plasmasphere in the postmidnight region and ...

Fennell, J.; Roeder, J.; Kurth, W.; Henderson, M.; Larsen, B.; Hospodarsky, G.; Wygant, J.; Claudepierre, J.; Blake, J.; Spence, H.; Clemmons, J.; Funsten, H.; Kletzing, C.; Reeves, G.;

YEAR: 2014     DOI: 10.1002/2013GL059165

Van Allen Probes

Nonstorm time dynamics of electron radiation belts observed by the Van Allen Probes

Storm time electron radiation belt dynamics have been widely investigated for many years. Here we present a rarely reported nonstorm time event of electron radiation belt evolution observed by the Van Allen Probes during 21\textendash24 February 2013. Within 2 days, a new belt centering around L=5.8 formed and gradually merged with the original outer belt, with the enhancement of relativistic electron fluxes by a factor of up to 50. Strong chorus waves (with power spectral density up to 10-4nT2/Hz) occurred in the region L>5 ...

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

YEAR: 2014     DOI: 10.1002/2013GL058912

Van Allen Probes


The Magnetic Electron Ion Spectrometer (MagEIS) Instruments Aboard the Radiation Belt Storm Probes (RBSP) Spacecraft

This paper describes the Magnetic Electron Ion Spectrometer (MagEIS) instruments aboard the RBSP spacecraft from an instrumentation and engineering point of view. There are four magnetic spectrometers aboard each of the two spacecraft, one low-energy unit (20\textendash240 keV), two medium-energy units (80\textendash1200 keV), and a high-energy unit (800\textendash4800 keV). The high unit also contains a proton telescope (55 keV\textendash20 MeV). The magnetic spectrometers focus electrons within a selected energy pass band ...

Blake, J.; Carranza, P.; Claudepierre, S.; Clemmons, J.; Crain, W.; Dotan, Y.; Fennell, J.; Fuentes, F.; Galvan, R.; George, J.; Henderson, M.; Lalic, M.; . Y. Lin, A; Looper, M.; Mabry, D.; Mazur, J.; McCarthy, B.; Nguyen, C.; textquoterightBrien, T.; Perez, M.; Redding, M.; Roeder, J.; Salvaggio, D.; Sorensen, G.; Spence, H.; Yi, S.; Zakrzewski, M.;

YEAR: 2013     DOI: 10.1007/s11214-013-9991-8

RBSP; Van Allen Probes

The Relativistic Proton Spectrometer (RPS) for the Radiation Belt Storm Probes Mission

The Relativistic Proton Spectrometer (RPS) on the Radiation Belt Storm Probes spacecraft is a particle spectrometer designed to measure the flux, angular distribution, and energy spectrum of protons from \~60 MeV to \~2000 MeV. RPS will investigate decades-old questions about the inner Van Allen belt proton environment: a nearby region of space that is relatively unexplored because of the hazards of spacecraft operation there and the difficulties in obtaining accurate proton measurements in an intense penetrating background. ...

Mazur, J.; Friesen, L.; Lin, A.; Mabry, D.; Katz, N.; Dotan, Y.; George, J.; Blake, J.; LOOPER, M; Redding, M.; textquoterightBrien, T.; Cha, J.; Birkitt, A.; Carranza, P.; Lalic, M.; Fuentes, F.; Galvan, R.; McNab, M.;

YEAR: 2013     DOI: 10.1007/s11214-012-9926-9

RBSP; Van Allen Probes

Science Goals and Overview of the Energetic Particle, Composition, and Thermal Plasma (ECT) Suite on NASA\textquoterights Radiation Belt Storm Probes (RBSP) Mission

The Radiation Belt Storm Probes (RBSP)-Energetic Particle, Composition, and Thermal Plasma (ECT) suite contains an innovative complement of particle instruments to ensure the highest quality measurements ever made in the inner magnetosphere and radiation belts. The coordinated RBSP-ECT particle measurements, analyzed in combination with fields and waves observations and state-of-the-art theory and modeling, are necessary for understanding the acceleration, global distribution, and variability of radiation belt electrons and ...

Spence, H.; Reeves, G.; Baker, D.; Blake, J.; Bolton, M.; Bourdarie, S.; Chan, A.; Claudpierre, S.; Clemmons, J.; Cravens, J.; Elkington, S.; Fennell, J.; Friedel, R.; Funsten, H.; Goldstein, J.; Green, J.; Guthrie, A.; Henderson, M.; Horne, R.; Hudson, M.; Jahn, J.-M.; Jordanova, V.; Kanekal, S.; Klatt, B.; Larsen, B.; Li, X.; MacDonald, E.; Mann, I.R.; Niehof, J.; O\textquoterightBrien, T.; Onsager, T.; Salvaggio, D.; Skoug, R.; Smith, S.; Suther, L.; Thomsen, M.; Thorne, R.;

YEAR: 2013     DOI: DOI: 10.1007/s11214-013-0007-5

RBSP; Van Allen Probes

Van Allen Probes observation of localized drift-resonance between poloidal mode ultra-low frequency waves and 60 keV electrons

[1] We present NASA Van Allen Probes observations of wave-particle interactions between magnetospheric ultra-low frequency (ULF) waves and energetic electrons (20\textendash500 keV) on 31 October 2012. The ULF waves are identified as the fundamental poloidal mode oscillation and are excited following an interplanetary shock impact on the magnetosphere. Large amplitude modulations in energetic electron flux are observed at the same period (≈ 3 min) as the ULF waves and are consistent with a drift-resonant interaction. The a ...

Claudepierre, S.; Mann, I.R.; Takahashi, K; Fennell, J.; Hudson, M.; Blake, J.; Roeder, J.; Clemmons, J.; Spence, H.; Reeves, G.; Baker, D.; Funsten, H.; Friedel, R.; Henderson, M.; Kletzing, C.; Kurth, W.; Wygant, J.;

YEAR: 2013     DOI: 10.1002/grl.50901

RBSP; Van Allen Probes

Excitation of Poloidal standing Alfven waves through the drift resonance wave-particle interaction

Drift-resonance wave-particle interaction is a fundamental collisionless plasma process studied extensively in theory. Using cross-spectral analysis of electric field, magnetic field, and ion flux data from the Van Allen Probe (Radiation Belt Storm Probes) spacecraft, we present direct evidence identifying the generation of a fundamental mode standing poloidal wave through drift-resonance interactions in the inner magnetosphere. Intense azimuthal electric field (Eφ) oscillations as large as 10mV/m are observed, associated w ...

Dai, L.; Takahashi, K; Wygant, J.; Chen, L.; Bonnell, J; Cattell, C.; Thaller, S.; Kletzing, C.; Smith, C.; MacDowall, R.; Baker, D.; Blake, J.; Fennell, J.; Claudepierre, S.; Funsten, H.; Reeves, G.; Spence, H.;

YEAR: 2013     DOI: 10.1002/grl.50800

RBSP; Van Allen Probes

Helium, Oxygen, Proton, and Electron (HOPE) Mass Spectrometer for the Radiation Belt Storm Probes Mission

The HOPE mass spectrometer of the Radiation Belt Storm Probes (RBSP) mission (renamed the Van Allen Probes) is designed to measure the in situ plasma ion and electron fluxes over 4π sr at each RBSP spacecraft within the terrestrial radiation belts. The scientific goal is to understand the underlying physical processes that govern the radiation belt structure and dynamics. Spectral measurements for both ions and electrons are acquired over 1 eV to 50 keV in 36 log-spaced steps at an energy resolution ΔE FWHM/E≈15 \%. The ...

Funsten, H.; Skoug, R.; Guthrie, A.; MacDonald, E.; Baldonado, J.; Harper, R.; Henderson, K.; Kihara, K.; Lake, J.; Larsen, B.; Puckett, A.; Vigil, V.; Friedel, R.; Henderson, M.; Niehof, J.; Reeves, G.; Thomsen, M.; Hanley, J.; George, D.; Jahn, J.-M.; Cortinas, S.; Santos, Los; Dunn, G.; Edlund, E.; Ferris, M.; Freeman, M.; Maple, M.; Nunez, C.; Taylor, T.; Toczynski, W.; Urdiales, C.; Spence, H.; Cravens, J.; Suther, L.; Chen, J.;

YEAR: 2013     DOI: 10.1007/s11214-013-9968-7

RBSP; Van Allen Probes

Electron Acceleration in the Heart of the Van Allen Radiation Belts

The Van Allen radiation belts contain ultrarelativistic electrons trapped in Earth\textquoterights magnetic field. Since their discovery in 1958, a fundamental unanswered question has been how electrons can be accelerated to such high energies. Two classes of processes have been proposed: transport and acceleration of electrons from a source population located outside the radiation belts (radial acceleration) or acceleration of lower-energy electrons to relativistic energies in situ in the heart of the radiation belts (local ...

Reeves, G.; Spence, H.; Henderson, M.; Morley, S.; Friedel, R.; Funsten, H.; Baker, D.; Kanekal, S.; Blake, J.; Fennell, J.; Claudepierre, S.; Thorne, R.; Turner, D.; Kletzing, C.; Kurth, W.; Larsen, B.; Niehof, J.;

YEAR: 2013     DOI: 10.1126/science.1237743

Van Allen Probes

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