College of Sciences and Mathematics: Recent submissions
Now showing items 261-280 of 389
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 ...
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, ...
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. ...
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 ...
Comparison of TWINS and THEMIS observations of proton pitch angle distributions in the ring current during the 29 May 2010 geomagnetic storm
(2020-06-09)
The first comparison between energy-dependent ion pitch angle distributions in the ring current deconvolved from Two Wide-angle Imagining Neutral-atom Spectrometers (TWINS) energetic neutral atom (ENA) images and measured ...
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. ...
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 ...
Experimental characterization of broadband electrostatic noise due to plasma compression
(2020-06-05)
For a wide variety of laboratory and space plasma environments, theoretical predictions state that plasmas are unstable to inhomogeneous flows over a very broad frequency range. Such sheared flows are generated in the ...
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 ...
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 ...
Investigation of storm time magnetotail and ion injection using three-dimensional global hybrid simulation
(2020-06-05)
Dynamics of the near-Earth magnetotail associated with substorms during a period of extended southward interplanetary magnetic field is studied using a three-dimensional (3-D) global hybrid simulation model that includes ...
The Comprehensive Inner Magnetosphere-Ionosphere Model
(2020-06-05)
Simulation studies of the Earth's radiation belts and ring current are very useful in understanding the acceleration, transport, and loss of energetic particles. Recently, the Comprehensive Ring Current Model (CRCM) and ...
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. ...
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 ...
Externally driven plasmaspheric ULF waves observed by the Van Allen Probes
(2020-06-05)
We analyze data acquired by the Van Allen Probes on 8 November 2012, during a period of extended low geomagnetic activity, to gain new insight into plasmaspheric ultralow frequency (ULF) waves. The waves exhibited strong ...
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, ...
Maskelynite formation via solid-state transformation: Evidence of infrared and X-ray anisotropy
(2020-06-05)
We present the results of a combined study of shocked labradorite from the Lonar crater, India, using optical microscopy, micro-Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, high-energy X-ray total ...
EUV emissions from solar wind charge exchange in the Earth's magnetosheath: Three-dimensional global hybrid simulation
(2020-06-05)
In this paper, a three-dimensional (3-D) global hybrid simulation code and a 3-D geocoronal hydrogen model are used to systematically study the extreme ultraviolet (EUV) emissions at 30.4nm produced by solar wind charge ...
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 ...