Found 5 entries in the Bibliography.

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Direct evidence of the pitch angle scattering of relativistic electrons induced by EMIC waves

In this study, we analyze an EMIC wave event of rising tone elements recorded by the Van Allen Probes. The pitch angle distributions of relativistic electrons exhibit a direct response to the two elements of EMIC waves: at the intermediate pitch angle the fluxes are lower and at the low pitch angle the fluxes are higher than those when no EMIC was observed. In particular, the observed changes in the pitch angle distributions are most likely to be caused by nonlinear wave particle interaction. The calculation of the minimum r ...

Zhu, Hui; Chen, Lunjin; Claudepierre, Seth; Zheng, Liheng;

YEAR: 2020     DOI: 10.1029/2019GL085637

EMIC waves; nonlinear wave-particle interaction; pitch angle scattering; Van Allen Probes


Properties of intense field-aligned lower-band chorus waves: Implications for nonlinear wave-particle interactions

Resonant interactions between electrons and chorus waves are responsible for a wide range of phenomena in near-Earth space (e.g., diffuse aurora, acceleration of MeV electrons, etc.). Although quasi-linear diffusion is believed to be the primary paradigm for describing such interactions, an increasing number of investigations suggest that nonlinear effects are also important in controlling the rapid dynamics of electrons. However, present models of nonlinear wave-particle interactions, which have been successfully used to de ...

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

YEAR: 2018     DOI: 10.1029/2018JA025390

chorus waves; Effective amplitude; nonlinear wave-particle interaction; spatial distribution; statistics; Van Allen Probes; Wave-packet length

Generation process of large-amplitude upper band chorus emissions observed by Van Allen Probes

We analyze large-amplitude upper-band chorus emissions measured near the magnetic equator by the EMFISIS (Electric and Magnetic Field Instrument Suite and Integrated Science) instrument package onboard the Van Allen Probes. In setting up the parameters of source electrons exciting the emissions based on theoretical analyses and observational results measured by the HOPE (Helium Oxygen Proton Electron) instrument, we calculate threshold and optimum amplitudes with the nonlinear wave growth theory. We find that the optimum amp ...

Kubota, Yuko; Omura, Yoshiharu; Kletzing, Craig; Reeves, Geoff;

YEAR: 2018     DOI: 10.1029/2017JA024782

Chorus; energetic electrons; nonlinear wave-particle interaction; observation; Radiation belt; Van Allen Probes


Formation process of relativistic electron flux through interaction with chorus emissions in the Earth\textquoterights inner magnetosphere

We perform test particle simulations of energetic electrons interacting with whistler mode chorus emissions. We compute trajectories of a large number of electrons forming a delta function with the same energy and equatorial pitch angle. The electrons are launched at different locations along the magnetic field line and different timings with respect to a pair of chorus emissions generated at the magnetic equator. We follow the evolution of the delta function and obtain a distribution function in energy and equatorial pitch ...

Omura, Yoshiharu; Miyashita, Yu; Yoshikawa, Masato; Summers, Danny; Hikishima, Mitsuru; Ebihara, Yusuke; Kubota, Yuko;

YEAR: 2015     DOI: 10.1002/2015JA021563

Chorus; nonlinear wave-particle interaction; Particle acceleration; Radiation belts; relativistic electrons; simulation


First observation of rising-tone magnetosonic waves

Magnetosonic (MS) waves are linearly polarized emissions confined near the magnetic equator with wave normal angle near 90\textdegree and frequency below the lower hybrid frequency. Such waves, also termed equatorial noise, were traditionally known to be \textquotedbllefttemporally continuous\textquotedblright in their time-frequency spectrogram. Here we show for the first time that MS waves actually have discrete wave elements with rising-tone features in their spectrogram. The frequency sweep rate of MS waves, ~1 Hz/s, is ...

Fu, H.; Cao, J.; Zhima, Z.; Khotyaintsev, Y.; Angelopoulos, V.; ik, O.; Omura, Y.; Taubenschuss, U.; Chen, L.; . Y. Huang, S;

YEAR: 2014     DOI: 10.1002/grl.v41.2110.1002/2014GL061867

discrete; frequency sweep rate; magnetosonic wave; nonlinear wave-particle interaction; Plasmapause; rising tone