Search Publications
Understanding shock dynamics in the inner heliosphere with modeling and type II radio data: A statistical study
St. Cyr, O. C.; Odstrcil, D.; Gopalswamy, N. +2 more
We study two methods of predicting interplanetary shock location and strength in the inner heliosphere: (1) the ENLIL simulation and (2) the kilometric type II (kmTII) prediction. To evaluate differences in the performance of the first method, we apply two sets of coronal mass ejections (CME) parameters from the cone-model fitting and flux-rope (F…
Nonlocal electron heating at the Earth's bow shock and the role of the magnetically tangent point
Schwartz, S. J.; Mitchell, J. J.
The solar wind interaction with the terrestrial magnetosphere results in a standing bow shock. Due to the shock's collisionless nature, the plasma in the magnetosheath is far from equilibrium. The highly mobile magnetosheath electrons move quickly between different points on the shock surface. Consequently, portions of phase space are populated wi…
Radial evolution of the three-dimensional structure in CIRs between Earth and Ulysses
Desai, M. I.; Broiles, T. W.; Lee, C. O. +1 more
The radial alignment of ACE and Ulysses in February 2004 and August 2007 provided us with unprecedented opportunities to study the radial evolution of planar magnetic structures (PMSs) in three corotating interaction regions (CIRs). The in situ observations are compared with results from an analytical and a numerical model of CIRs. We find that (1…
On the Field-Aligned Beam Thermal Energy
Mazelle, C.; Wilber, M.; Meziane, K. +2 more
The parallel and perpendicular reduced distribution functions of field-aligned beams (FABs) observed upstream of the Earth's bow shock using the Cluster spacecrafts are examined. A previous study revealed that FABs, observed in oblique shock geometries, exhibit reduced distribution functions with high-energy tails. A selection of FABs with weak-en…
He2+ transport in the Martian upper atmosphere with an induced magnetic field
Barabash, S.; Stenberg, G.; Shematovich, V. I. +3 more
wind helium may be a significant source of neutral helium in the Martian atmosphere. The precipitating particles also transfer mass, energy, and momentum. To investigate the transport of He2+ in the upper atmosphere of Mars, we have applied the direct simulation Monte Carlo method to solve the kinetic equation. We calculate the upward H…
Frequency drift of Saturn chorus emission compared to nonlinear theory
Gurnett, D. A.; Hospodarsky, G. B.; Menietti, J. D. +1 more
The fine structure of nonlinear drifting-frequency chorus is observed at Saturn by the Cassini Radio and Plasma Wave Investigation. During a high-inclination orbit in which Cassini is at near-constant L-shell within about 10° of the magnetic equator, moderately intense nonlinear chorus is observed. Cassini observed a region of intense chorus and l…
Longitudinal modulation of the brightness of Io's auroral footprint emission: Comparison with models
Bagenal, F.; Nichols, J. D.; Clarke, J. T. +3 more
auroral emission close to the foot of Io's magnetic flux tube has been known for over a decade to be one of the key parameters characterizing the electrodynamic interaction between the satellite and Jupiter's magnetosphere. Ten years of observations of Io's magnetic footprint brightness have been conducted via far ultraviolet imaging by two instru…
Axis and velocity determination for quasi two-dimensional plasma/field structures from Faraday's law: A second look
Hasegawa, Hiroshi; Swisdak, M.; Sonnerup, Bengt U. Ö. +1 more
We re-examine the basic premises of a single-spacecraft data analysis method, developed by Sonnerup and Hasegawa (2005), for determining the axis orientation and proper frame velocity of quasi two-dimensional, quasi-steady structures of magnetic field and plasma. The method, which is based on Faraday's law, makes use of magnetic and electric field…
Pseudo altitude: A new perspective on the auroral density cavity
Karlsson, T.; Masson, A.; Marklund, G. T. +1 more
Studying the density distribution inside the auroral density cavity is complicated by the difficulties in achieving simultaneous measurements within the same flux tube at different altitudes. Comparisons between different events are complicated by variations in both the location of the density cavity and the location of the related potential struc…
Enceladus auroral hiss observations: Implications for electron beam locations
Gurnett, D. A.; Hospodarsky, G. B.; Leisner, J. S.
<title type="main">Abstract<p label="1">The Cassini spacecraft has made 20 close flybys of the icy moon Enceladus between its arrival at Saturn in 2004 and 2012. Of those 20, strong whistler mode emissions (often called auroral hiss) were clearly observed on seven encounters. The propagation paths of these emissions are determined by t…