Browsing Physics by Title
Now showing items 46-65 of 91
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 ...
Lattice thermal conductivity of MgO at conditions of Earth's interior
(2020-06-29)
Thermal conductivity of the Earth’s lower mantle greatly impacts the mantle convection style and affects the heat conduction from the core to the mantle. Direct laboratory measurement of thermal conductivity of mantle ...
Magnetic field rotation and transition width in rotational discontinuities and Alfven wave trains
(2020-06-30)
A hybrid simulation is carried out to study the evolution of magnetic field rotations in rotational discontinuities (RDs) and large-amplitude Alfven wave trains (AWTs) whose initial field rotation angle \Delta Phi\ > 180 ...
Magnetic flux rope formation within a magnetosheath hot flow anomaly
(2020-06-09)
We report observations on 1 March 2004 by the Cluster spacecraft of a hot flow anomaly (HFA) encountered in the dayside magnetosheath near Earth's bow shock. Embedded within the HFA was a magnetic flux rope with a diameter ...
Magnetosheath Reconnection Before Magnetopause Reconnection Driven by Interplanetary Tangential Discontinuity: A Three-Dimensional Global Hybrid Simulation With Oblique Interplanetary Magnetic Field
(2020-05-28)
Terrestrial dayside dynamics associated with a southward turning, oblique interplanetary magnetic field (IMF) carried by an interplanetary tangential discontinuity (TD) is investigated by performing a three-dimensional ...
Modeling of a New Electron Acceleration Mechanism Ahead of Streamers
(2020-05-26)
Head‐on collisions between negative and positive streamers have been proposed as a mechanism behind X‐ray emissions by laboratory spark discharges. Recent simulations using plasma fluid and particle in cell models of a ...
Modeling the loss of inner belt protons by magnetic field line curvature scattering
(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 ...
The NSF/DOE Partnership in Basic Plasma Science & Engineering at 20: Report on the Anniversary Workshop
(2019-11-11)
A workshop recognizing the 20th anniversary of the NSF/DOE Partnership in Basic Plasma Science and Engineering was held at NSF on January 9-11, 2017. The workshop demonstrated some of the remarkable research and broader ...
One- and two-dimensional hybrid simulations of whistler mode waves in a dipole field
(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 ...
Outflow from the ionosphere in the vicinity of the cusp
(2020-06-26)
Low-energy ion outflows from the ionosphere are known to be an important source of plasma for the magnetosphere. The objective of this study is to describe the spatial relationships between low-energy ionospheric outflows ...
Overlap of the plasmasphere and ring current: Relation to subauroral ionospheric heating
(2020-06-18)
The overlap of the ring current with the outer plasmasphere is thought to play a major role in storm-time related increases in the subauroral ambient topside electron temperature. Instabilities generated within the overlap ...
Oxygen-hydrogen differentiated observations from TWINS: The 22 July 2009 storm
(2020-06-09)
The 22 July 2009 magnetic storm is the first significant storm during the emergence of the recent prolonged solar cycle minimum. This moderate storm (minimum Dst approximately -78 nT) has received a good deal of attention ...
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. ...
Pickup proton instabilities and scattering in the distant solar wind and the outer heliosheath: Hybrid simulations
(2020-06-09)
The growth of magnetic field fluctuations driven by the injection of pickup ions perpendicular to a background magnetic field in a homogeneous, collisionless plasma is studied using one-dimensional hybrid simulations. ...
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 ...
Proton velocity ring-driven instabilities in the inner magnetosphere: Linear theory and particle-in-cell simulations
(2020-06-03)
Linear dispersion theory and electromagnetic particle-in-cell (PIC) simulations are used to investigate linear growth and nonlinear saturation of the proton velocity ring-driven instabilities, namely, ion Bernstein instability ...
Quiet time equatorial mass density distribution derived from AMPTE/CCE and GOES using the magnetoseismology technique
(2020-06-05)
An inversion technique for estimating the properties of the magnetospheric plasma from the harmonic frequencies of the toroidal standing Alfven waves has been used to derive the global equatorial mass density covering ...
Radiation pressure measurements on micron-size individual dust grains
(2020-06-18)
Measurements of electromagnetic radiation pressure have been made on individual silica (SiO2) particles levitated in an electrodynamic balance. These measurements were made by inserting single charged particles of known ...
Regime transition of ion Bernstein instability driven by ion shell velocity distributions
(2020-06-03)
Linear kinetic dispersion theory is used to investigate a regime transition of the ion Bernstein instability driven by a proton velocity distribution with positive slopes with respect to the perpendicular velocity, ...
Reversal of magnetic field rotation in the reconnection layer due to shear flow effects
(2020-06-18)
We investigate the effects of shear flows on the so-called "component reconnection," in which the guide field B-y not equal 0, by solving a one-dimensional Riemann problem for magnetopause reconnection using a resistive ...