Physics: Recent submissions
Now showing items 161-180 of 192
Scalings of Alfven-cyclotron and ion Bernstein instabilities on temperature anisotropy of a ring-like velocity distribution in the inner magnetosphere
(2020-06-03)
A ring-like proton velocity distribution with f(p)(v)/v>0 and which is sufficiently anisotropic can excite two distinct types of growing modes in the inner magnetosphere: ion Bernstein instabilities with multiple ion ...
Statistical correlation of low-altitude ENA emissions with geomagnetic activity from IMAGE/MENA observations
(2020-06-03)
Plasma sheet particles transported Earthward during times of active magnetospheric convection can interact with exospheric/thermospheric neutrals through charge exchange. The resulting Energetic Neutral Atoms (ENAs) are ...
Understanding the growth rate patterns of ion Bernstein instabilities driven by ring-like proton velocity distributions
(2020-06-03)
Fast magnetosonic waves in Earth's inner magnetosphere, which have as their source ion Bernstein instabilities, are driven by hot proton velocity distributions (f(p)) with partial derivative f(p)(v(perpendicular to))/partial ...
Ion Bernstein instability dependence on the proton-to-electron mass ratio: Linear dispersion theory
(2020-06-03)
Fast magnetosonic waves, which have as their source ion Bernstein instabilities driven by tenuous ring-like proton velocity distributions, are frequently observed in the inner magnetosphere. One major difficulty in the ...
Kinetic Alfven waves in three-dimensional magnetic reconnection
(2020-06-03)
Alfvenic waves are believed to be fundamentally important in magnetic reconnection. Kinetic dynamics of particles can break the Alfven speed limit in the evolution and propagation of perturbations during reconnection. In ...
Global images of trapped ring current ions during main phase of 17 March 2015 geomagnetic storm as observed by TWINS
(2020-06-03)
A unique view of the trapped particles in the inner magnetosphere provided by energetic neutral atom (ENA) imaging is used to observe the dynamics of the spatial structure and the pitch angle anisotropy on a global scale ...
Hall effect control of magnetotail dawn-dusk asymmetry: A three-dimensional global hybrid simulation
(2020-06-03)
Magnetotail reconnection and related phenomena (e.g., flux ropes, dipolarizing flux bundles, flow bursts, and particle injections) occur more frequently on the duskside than on the dawnside. Because this asymmetry can ...
Scalings for the Alfven-cyclotron instability: Linear dispersion theory and hybrid particle-in-cell simulations
(2020-06-01)
The Alfven-cyclotron instability is driven by an ion temperature anisotropy such that T-perpendicular to/T-|| >1 where and || denote directions perpendicular and parallel to a uniform background magnetic field B-o, ...
Cross-scale observations of the 2015 St. Patrick's day storm: THEMIS, Van Allen Probes, and TWINS
(2020-06-01)
We present cross-scale magnetospheric observations of the 17 March 2015 (St. Patrick's Day) storm, by Time History of Events and Macroscale Interactions during Substorms (THEMIS), Van Allen Probes (Radiation Belt Storm ...
Ion Bernstein instability as a possible source for oxygen ion cyclotron harmonic waves
(2020-06-01)
This paper demonstrates that an ion Bernstein instability can be a possible source for recently reported electromagnetic waves with frequencies at or near the singly ionized oxygen ion cyclotron frequency, Omega(+)(O), and ...
Spectral properties and associated plasma energization by magnetosonic waves in the Earth's magnetosphere: Particle-in-cell simulations
(2020-06-01)
In this paper, we perform a 1-D particle-in-cell (PIC) simulation model consisting of three species, cold electrons, cold ions, and energetic ion ring, to investigate spectral structures of magnetosonic waves excited by ...
Foreshock wave interaction with the magnetopause: Signatures of mode conversion
(2020-06-01)
Our previous hybrid simulation (Shi et al., 2013) under a radial interplanetary magnetic field (IMF) and a supercritical solar wind Mach number has shown that foreshock compressional waves originated from the quasi-parallel ...
The ion temperature gradient: An intrinsic property of Earth's magnetotail
(2020-06-01)
Although the ion temperature gradient along (X GSM) and across (Z GSM) the Earth's magnetotail, which plays a key role in generating the cross‐tail current and establishing pressure balance with the lobes, has been extensively ...
Generation of rising-tone chorus in a two-dimensional mirror field by using the general curvilinear PIC code
(2020-05-29)
Recently, the generation of rising-tone chorus has been implemented with one-dimensional (1-D) particle-in-cell (PIC) simulations in an inhomogeneous background magnetic field, where both the propagation of waves and motion ...
Proton velocity ring-driven instabilities and their dependence on the ring speed: Linear theory
(2020-05-28)
Linear dispersion theory is used to study the Alfven-cyclotron, mirror and ion Bernstein instabilities driven by a tenuous (1%) warm proton ring velocity distribution with a ring speed, v(r), varying between 2v(A) and ...
Ring/Shell Ion Distributions at Geosynchronous Orbit
(2020-05-28)
One year's worth of plasma observations from geosynchronous orbit is examined for ion distributions that may simultaneously be subject to the ion Bernstein (IB) instability (generating fast magnetosonic waves) and the ...
Fast Magnetosonic Waves Observed by Van Allen Probes: Testing Local Wave Excitation Mechanism
(2020-05-28)
Linear Vlasov theory and particle-in-cell (PIC) simulations for electromagnetic fluctuations in a homogeneous, magnetized, and collisionless plasma are used to investigate a fast magnetosonic wave event observed by the Van ...
Ion Acceleration Inside Foreshock Transients
(2020-05-28)
Recent observations upstream of Earth's bow shock have revealed that foreshock transients can not only accelerate solar wind ions by reflection at their upstream boundaries but may also accelerate ions inside them. Evidence ...
Particle-in-Cell Simulations of the Fast Magnetosonic Mode in a Dipole Magnetic Field: 1-D Along the Radial Direction
(2020-05-28)
An electromagnetic particle-in-cell code is used to investigate self-consistent evolution of the fast magnetosonic mode in a one-dimensional configuration along the radial direction in a dipole background magnetic field. ...
Equatorial Evolution of the Fast Magnetosonic Mode in the Source Region: Observation-Simulation Comparison of the Preferential Propagation Direction
(2020-05-28)
Recent analysis of an event observed by the Van Allen Probes in the source region outside the plasmapause has shown that fast magnetosonic waves (also referred to as equatorial noise) propagate preferentially in the azimuthal ...