Search Publications
Kinetic structures of quasi-perpendicular shocks in global particle-in-cell simulations
Henri, Pierre; Khotyaintsev, Yuri; Johlander, Andreas +5 more
We carried out global Particle-in-Cell simulations of the interaction between the solar wind and a magnetosphere to study the kinetic collisionless physics in super-critical quasi-perpendicular shocks. After an initial simulation transient, a collisionless bow shock forms as a result of the interaction of the solar wind and a planet magnetic dipol…
Evolution of Kelvin-Helmholtz instability at Venus in the presence of the parallel magnetic field
Zhang, T. L.; Cao, J. B.; Fu, H. S. +2 more
Two-dimensional MHD simulations were performed to study the evolution of the Kelvin-Helmholtz (KH) instability at the Venusian ionopause in response to the strong flow shear in presence of the in-plane magnetic field parallel to the flow direction. The physical behavior of the KH instability as well as the triggering and occurrence conditions for …
Pitch-angle diffusion of electrons through growing and propagating along a magnetic field electromagnetic wave in Earth's radiation belts
Park, Y. -D.; Dokgo, K.; Lee, D. -Y. +5 more
The diffusion of electrons via a linearly polarized, growing electromagnetic (EM) wave propagating along a uniform magnetic field is investigated. The diffusion of electrons that interact with the growing EM wave is investigated through the autocorrelation function of the parallel electron acceleration in several tens of electron gyration timescal…
Stochastic acceleration of ions driven by Pc1 wave packets
Sibeck, D. G.; Khazanov, G. V.; Tel'nikhin, A. A. +1 more
The stochastic motion of protons and He+ ions driven by Pc1 wave packets is studied in the context of resonant particle heating. Resonant ion cyclotron heating typically occurs when wave powers exceed 10-4 nT2/Hz. Gyroresonance breaks the first adiabatic invariant and energizes keV ions. Cherenkov resonances with t…
Study of localized structures of kinetic Alfvén wave and generation of turbulence
Sharma, R. P.; Kumari, Anju; Yadav, Nitin
Localization of kinetic Alfvén waves (KAW) due to ponderomotive nonlinearity can be regarded as an important mechanism for heating the space plasmas. The present paper investigates the effect of background density fluctuations on the formation of large amplitude localized structures and turbulent spectrum of KAW applicable to magnetopause. The dyn…
The link between shocks, turbulence, and magnetic reconnection in collisionless plasmas
Sibeck, D.; Nykyri, K.; Daughton, W. +11 more
Global hybrid (electron fluid, kinetic ions) and fully kinetic simulations of the magnetosphere have been used to show surprising interconnection between shocks, turbulence, and magnetic reconnection. In particular, collisionless shocks with their reflected ions that can get upstream before retransmission can generate previously unforeseen phenome…
Computing the reconnection rate in turbulent kinetic layers by using electron mixing to identify topology
Daughton, W.; Nakamura, T. K. M.; Karimabadi, H. +2 more
Three-dimensional kinetic simulations of magnetic reconnection for parameter regimes relevant to the magnetopause current layer feature the development of turbulence, driven by the magnetic and velocity shear, and dominated by coherent structures including flux ropes, current sheets, and flow vortices. Here, we propose a new approach for computing…
Energy dissipation by whistler turbulence: Three-dimensional particle-in-cell simulations
Chang, Ouliang; Wang, Joseph; Peter Gary, S.
Three-dimensional particle-in-cell simulations of whistler turbulence are carried out on a collisionless, homogeneous, magnetized plasma model. The simulations use an initial ensemble of relatively long wavelength whistler modes and follow the temporal evolution of the fluctuations as they cascade into a broadband, anisotropic, turbulent spectrum …
A review of pressure anisotropy caused by electron trapping in collisionless plasma, and its implications for magnetic reconnection
Daughton, William; Egedal, Jan; Le, Ari
From spacecraft data, it is evident that electron pressure anisotropy develops in collisionless plasmas. This is in contrast to the results of theoretical investigations, which suggest this anisotropy should be limited. Common for such theoretical studies is that the effects of electron trapping are not included; simply speaking, electron trapping…
Nonlinear electron acceleration by oblique whistler waves: Landau resonance vs. cyclotron resonance
Artemyev, A. V.; Agapitov, O. V.; Krasnoselskikh, V. V. +2 more
This paper is devoted to the study of the nonlinear interaction of relativistic electrons and high amplitude strongly oblique whistler waves in the Earth's radiation belts. We consider electron trapping into Landau and fundamental cyclotron resonances in a simplified model of dipolar magnetic field. Trapping into the Landau resonance corresponds t…