Found 12 entries in the Bibliography.

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Statistical occurrence and distribution of high amplitude whistler-mode waves in the outer radiation belt

We present the first statistical analysis with continuous data coverage and non-averaged amplitudes of the prevalence and distribution of high-amplitude (> 5 mV/m) whistler-mode waves in the outer radiation belt using 5 years of Van Allen Probes data. These waves are most common above L=3.5 and between MLT of 0-7 where they are present 1-4\% of the time. During high geomagnetic activity, high-amplitude whistler-mode wave occurrence rises above 30\% in some regions. During these active times the plasmasphere erodes to lower ...

Tyler, E.; Breneman, A.; Cattell, C.; Wygant, J.; Thaller, S.; Malaspina, D.;

YEAR: 2019     DOI: 10.1029/2019GL082292

Chorus; Radiation belt; Van Allen belt; Van Allen Probes; Whistler waves


Longitudinal dependence of whistler mode electromagnetic waves in the Earth\textquoterights inner magnetosphere

We use the measurements performed by the DEMETER (2004-2010) and the Van Allen Probes (2012-2016, still operating) spacecraft to investigate the longitudinal dependence of the intensity of whistler mode waves in the Earth\textquoterights inner magnetosphere. We show that a significant longitudinal dependence is observed inside the plasmasphere on the nightside, primarily in the frequency range 400 Hz\textendash2 kHz. On the other hand, almost no longitudinal dependence is observed on the dayside. The obtained results are com ...

ahlava, J.; emec, F.; ik, O.; a, I.; Hospodarskyy, G.; Parrot, M.; Kurth, W.; Bortnik, J.; Kletzing, C.;

YEAR: 2018     DOI: 10.1029/2018JA025284

DEMETER; Van Allen Probes; Whistler waves

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


Roles of hot electrons in generating upper-hybrid waves in the earth\textquoterights radiation belt

Electrostatic fluctuations near upper-hybrid frequency, which are sometimes accompanied by multiple-harmonic electron cyclotron frequency bands above and below the upper-hybrid frequency, are common occurrences in the Earth\textquoterights radiation belt, as revealed through the twin Van Allen Probe spacecrafts. It is customary to use the upper-hybrid emissions for estimating the background electron density, which in turn can be used to determine the plasmapause locations, but the role of hot electrons in generating such flu ...

Hwang, J.; Shin, D.; Yoon, P.; Kurth, W.; Larsen, B.; Reeves, G.; . Y. Lee, D;

YEAR: 2017     DOI: 10.1063/1.4984249

Hot carriers; Magnetized plasmas; Radiation belts; Singing; Van Allen Probes; Whistler waves

Analysis of self-consistent nonlinear wave-particle interactions of whistler waves in laboratory and space plasmas

Whistler mode chorus is one of the most important emissions affecting the energization of the radiation belts. Recent laboratory experiments that inject energetic electron beams into a cold plasma have revealed several spectral features in the nonlinear evolution of these instabilities that have also been observed in high-time resolution in situ wave-form data. These features include (1) a sub-element structure which consists of an amplitude modulation on time-scales slower than the bounce time, (2) closely spaced discrete f ...

Crabtree, Chris; Ganguli, Gurudas; Tejero, Erik;

YEAR: 2017     DOI: 10.1063/1.4977539

Dispersion relations; Electron beams; SingingEigenvalues; Van Allen Probes; Whistler waves

Transverse eV ion heating by random electric field fluctuations in the plasmasphere

Charged particle acceleration in the Earth inner magnetosphere is believed to be mainly due to the local resonant wave-particle interaction or particle transport processes. However, the Van Allen Probes have recently provided interesting evidence of a relatively slow transverse heating of eV ions at distances about 2\textendash3 Earth radii during quiet times. Waves that are able to resonantly interact with such very cold ions are generally rare in this region of space, called the plasmasphere. Thus, non-resonant wave-partic ...

Artemyev, A.; Mourenas, D.; Agapitov, O.; Blum, L.;

YEAR: 2017     DOI: 10.1063/1.4976713

electric fields; Electrostatic Waves; protons; Van Allen Probes; Wave power; Whistler waves


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


Laboratory studies of nonlinear whistler wave processes in the Van Allen radiation belts

Important nonlinear wave-wave and wave-particle interactions that occur in the Earth\textquoterights Van Allen radiation belts are investigated in a laboratory experiment. Predominantly electrostatic waves in the whistler branch are launched that propagate near the resonance cone with measured wave normal angle greater than 85\textordmasculine. When the pump amplitude exceeds a threshold ~5 x10^6 times the back- ground magnetic field, wave power at frequencies below the pump frequency is observed at wave normal angles (~55\t ...

Tejero, E.; Crabtree, C.; Blackwell, D.; Amatucci, W.; Mithaiwala, M.; Ganguli, G.; Rudakov, L.;

YEAR: 2015     DOI: 10.1063/1.4928944

Electrostatic Waves; magnetic fields; Nonlinear scattering; Plasma electromagnetic waves; Whistler waves

Stability of relativistic electron trapping by strong whistler or electromagnetic ion cyclotron waves

In the present paper, we investigate the trapping of relativistic electrons by intense whistler-mode waves or electromagnetic ion cyclotron waves in the Earth\textquoterights radiation belts. We consider the non-resonant impact of additional, lower amplitude magnetic field fluctuations on the stability of electron trapping. We show that such additional non-resonant fluctuations can break the adiabatic invariant corresponding to trapped electron oscillations in the effective wave potential. This destruction results in a diffu ...

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

YEAR: 2015     DOI: 10.1063/1.4927774

Cyclotron resonances; magnetic fields; Particle fluctuations; Plasma electromagnetic waves; Whistler waves

One- and two-dimensional hybrid simulations of whistler mode waves in a dipole field

We simulate whistler mode waves using a hybrid code. There are four species in the simulations, hot electrons initialized with a bi-Maxwellian distribution with temperature in the direction perpendicular to background magnetic field greater than that in the parallel direction, warm isotropic electrons, cold inertialess fluid electrons, and protons as an immobile background. The density of the hot population is a small fraction of the total plasma density. Comparison between the dispersion relation of our model and other disp ...

Wu, S.; Denton, R.; Liu, K.; Hudson, M.;

YEAR: 2015     DOI: 10.1002/2014JA020736

hybrid simulation; particle-in-cell simulation; plasma waves; Whistler waves


Relativistic electron precipitation events driven by electromagnetic ion-cyclotron waves

We adopt a canonical approach to describe the stochastic motion of relativistic belt electrons and their scattering into the loss cone by nonlinear EMIC waves. The estimated rate of scattering is sufficient to account for the rate and intensity of bursty electron precipitation. This interaction is shown to result in particle scattering into the loss cone, forming \~10 s microbursts of precipitating electrons. These dynamics can account for the statistical correlations between processes of energization, pitch angle scattering ...

Khazanov, G.; Sibeck, D.; Tel\textquoterightnikhin, A.; Kronberg, T.;

YEAR: 2014     DOI: 10.1063/1.4892185

Diffusion; Electron scattering; Nonlinear waves; wave-particle interactions; Whistler waves


Weak turbulence in the magnetosphere: Formation of whistler wave cavity by nonlinear scattering

We consider the weak turbulence of whistler waves in the in low-β inner magnetosphere of the earth. Whistler waves, originating in the ionosphere, propagate radially outward and can trigger nonlinear induced scattering by thermal electrons provided the wave energy density is large enough. Nonlinear scattering can substantially change the direction of the wave vector of whistler waves and hence the direction of energy flux with only a small change in the frequency. A portion of whistler waves return to the ionosphere with a ...

Crabtree, C.; Rudakov, L.; Ganguli, G.; Mithaiwala, M.; Galinsky, V.; Shevchenko, V.;

YEAR: 2012     DOI: 10.1063/1.3692092

Whistler waves; Magnetosphere