Browsing Physics by Issue Date
Now showing items 61-80 of 192
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 hybrid simulation of mode conversion at the dayside magnetopause
(2020-06-05)
Mode conversion at the magnetopause has been suggested to lead to the generation of kinetic Alfven waves (KAWs) and effective mass transport from the solar wind into the magnetosphere. To investigate the mode conversion ...
Field line distribution of mass density at geostationary orbit
(2020-06-05)
The distribution of mass density along the field lines affects the ratios of toroidal (azimuthally oscillating) Alfven frequencies, and given the ratios of these frequencies, we can get information about that distribution. ...
Solar cycle variation of plasma mass density in the outer magnetosphere: Magnetoseismic analysis of toroidal standing Alfven waves detected by Geotail
(2020-06-05)
We study the variation of plasma mass density in the outer magnetosphere over a solar cycle using mass density estimated from the frequency of fundamental toroidal standing Alfven waves observed by the Geotail spacecraft. ...
TWINS stereoscopic imaging of multiple peaks in the ring current
(2020-06-05)
Global, ion equatorial flux distributions and energy spectra are presented from stereoscopic Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) 1 and TWINS 2 energetic neutral atom (ENA) images for two time periods, ...
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 ...
Signatures of electron Landau resonant interactions with chorus waves from THEMIS observations
(2020-06-05)
Simultaneous observations of electron phase space density (PSD) and chorus waves for more than 4 years by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) are analyzed to identify signatures ...
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 ...
Three-dimensional MHD simulations of interplanetary rotational discontinuities impacting the Earth's bow shock and magnetosheath
(2020-06-30)
The first ever fully three-dimensional magnetohydrodynamic (MHD) simulations of the detailed effects of MHD discontinuities on the magnetosheath have been performed. The simulation results predict that the interaction ...
Two-dimensional hybrid simulation of the dayside reconnection layer and associated ion transport
(2020-06-30)
The structure of the reconnection layer at the dayside magnetopause is studied by using a two-dimensional (2-D) hybrid code. The simulation domain is a rectangle in the at plane around an X line at the magnetopause. In our ...
Trapped and precipitating protons in the inner magnetosphere as seen by IMAGE
(2020-06-18)
[1] Images from the IMAGE satellite of precipitating protons (SU12/FUV) and trapped protons at 8.5 (MENA) and 33 keV (HENA) are compared during three periods: ( 1) 12 August 2000 from 1000 UT to 1145 UT just after the peak ...
Generation of near-Earth reconnection by divergent flows in the plasma sheet
(2020-06-25)
A global two-dimensional hybrid simulation is carried out to study the evolution of the near-Earth plasma sheet. It is shown that reconnection X lines and plasmoids can be generated by diverging flows in the plasma sheet. ...
Intermediate shocks in three-dimensional magnetohydrodynamic bow-shock flows with multiple interacting shock fronts
(2020-06-18)
Previous MHD simulations predict that when switch-on shock conditions obtain in the solar wind, the bow shock produced in front of an ellipsoidal obstacle will produce a unique bow shock configuration that includes a concave ...
Evolution of CIR storm on 22 July 2009
(2020-06-09)
Global images of ion intensities are deconvolved from TWINS ENA images during the main and recovery phase of a CIR storm on 22 July 2009. The global spatial ion images taken at different times, along with solar wind data, ...
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 ...
Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations
(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 ...
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 ...
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 ...
Two-Dimensional gcPIC Simulation of Rising-Tone Chorus Waves in a Dipole Magnetic Field
(2020-05-26)
Rising-tone chorus waves have already been successfully produced in a mirror magnetic field with the use of one- and two-dimensional particle-in-cell (PIC) simulations. However, in reality, the background magnetic field ...
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 ...