Browsing College of Sciences and Mathematics by Author "Kaijun Liu"

Now showing items 1-10 of 10

Equatorial Evolution of the Fast Magnetosonic Mode in the Source Region: Observation-Simulation Comparison of the Preferential Propagation Direction

Min, Kyungguk; Boardsen, Scott A.; Denton, Richard E.; Liu, Kaijun; 0000-0001-5882-1328 (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 ...

Ion Bernstein instability as a possible source for oxygen ion cyclotron harmonic waves

Min, Kyungguk; Denton, Richard E.; Liu, Kaijun; Gary, S. Peter; Spence, Harlan E.; 0000-0001-5882-1328 (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 ...

Ion Bernstein instability dependence on the proton-to-electron mass ratio: Linear dispersion theory

Min, Kyungguk; Liu, Kaijun; 0000-0002-2095-8529; 0000-0001-5882-1328 (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 ...

Modeling the loss of inner belt protons by magnetic field line curvature scattering

Tu, Weichao; Cowee, M. M.; Liu, Kaijun; 0000-0001-5882-1328 (2020-06-05)

The sudden loss of energetic protons in the inner radiation belt has been observed during geomagnetic storms. It is hypothesized that this sudden loss occurs because of changes in the geomagnetic field configuration which ...

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

Wu, S.; Denton, R. E.; Liu, Kaijun; Hudson, M. K.; 0000-0001-5882-1328 (2020-06-05)

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 ...

Particle-in-Cell Simulations of the Fast Magnetosonic Mode in a Dipole Magnetic Field: 1-D Along the Radial Direction

Min, Kyungguk; Liu, Kaijun; Denton, Richard E.; Boardsen, Scott A.; 0000-0001-5882-1328 (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. ...

Proton velocity ring-driven instabilities and their dependence on the ring speed: Linear theory

Min, Kyungguk; Liu, Kaijun; Gary, S. Peter; 0000-0001-5882-1328 (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

Thomsen, M. F.; Denton, M. H.; Gary, S. P.; Liu, Kaijun; Min, Kyungguk; 0000-0001-5882-1328 (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 ...

Scalings for the Alfven-cyclotron instability: Linear dispersion theory and hybrid particle-in-cell simulations

Gary, S. Peter; Fu, Xiangrong; Cowee, Misa M.; Winske, Dan; Liu, Kaijun; 0000-0001-5882-1328 (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, ...

Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations

Fu, Xiangrong; Liu, Kaijun; Min, Kyungguk; Winske, Dan; 0000-0001-5882-1328; 0000-0002-2095-8529 (2020-06-05)

Magnetospheric banded chorus is enhanced whistler waves with frequencies (r)<(e), where (e) is the electron cyclotron frequency, and a characteristic spectral gap at (r)similar or equal to(e)/2. This paper uses spacecraft ...