Search Publications
Whistler turbulence forward cascade: Three-dimensional particle-in-cell simulations
Chang, Ouliang; Wang, Joseph; Peter Gary, S.
The first fully three-dimensional particle-in-cell (PIC) simulation of whistler turbulence in a magnetized, homogeneous, collisionless plasma has been carried out. An initial relatively isotropic spectrum of long-wavelength whistlers is imposed upon the system, with an initial electron β = 0.10. As in previous two-dimensional simulations of whistl…
Simultaneous Cassini VIMS and UVIS observations of Saturn's southern aurora: Comparing emissions from H, H2 and H3+ at a high spatial resolution
Brown, R. H.; Baines, K. H.; Badman, S. V. +7 more
Here, for the first time, temporally coincident and spatially overlapping Cassini VIMS and UVIS observations of Saturn's southern aurora are presented. Ultraviolet auroral H and H2 emissions from UVIS are compared to infrared H3+ emission from VIMS. The auroral emission is structured into three arcs - H, H2
Limits of Enceladus's ice shell thickness from tidally driven tiger stripe shear failure
Pappalardo, Robert T.; Olgin, John G.; Smith-Konter, Bridget R.
Enceladus's south polar thermal anomaly and water-rich plumes suggest the existence of a subsurface ocean, which is overlain by an ice shell of uncertain thickness. Our objective is to constrain Enceladus's ice shell thickness, through assessment of tidally driven Coulomb failure of Enceladus's tiger stripe faults. We find that thin to moderate ic…
Intense plasma wave emissions associated with Saturn's moon Rhea
Schippers, P.; Gurnett, D. A.; Russell, C. T. +7 more
Measurements by the Cassini spacecraft during a close flyby of Saturn's moon Rhea on March 2, 2010, show the presence of intense plasma waves in the magnetic flux tube connected to the surface of the moon. Three types of waves were observed, (1) bursty electrostatic waves near the electron plasma frequency, (2) intense whistler-mode emissions belo…
Scattering function for energetic neutral hydrogen atoms off the lunar surface
Barabash, S.; Holmström, M.; Futaana, Y. +7 more
The Sub-keV Atom Reflecting Analyzer instrument on board the lunar orbiter Chandrayaan-1 provided a large number of measurements of lunar energetic neutral atoms (ENAs). These ENAs were formerly solar wind ions, which were neutralized and backscattered from the lunar surface. The angles under which the ENAs are scattered strongly depend on the sol…
Low-altitude acceleration of ionospheric ions at Mars
Barabash, S.; Lundin, R.; Yamauchi, M. +2 more
The objective of this study is to understand the acceleration processes that lead to outflow and escape of ionospheric ions from Mars. Observations show that accelerated dayside and flank ionospheric ions move slowly antisunward along the direction of the external/magnetosheath flow. At high altitudes, in the central tail, ions are further acceler…
Large-amplitude whistler waves and electron acceleration
Yoon, Peter H.
A recent observation shows that large-amplitude whistler waves propagating obliquely with respect to the ambient magnetic field may be responsible for energizing the radiation belt electrons to relativistic energies (MeV) within a time scale as short as a fraction of a second. Test-particle simulations available in the literature invariably adopt …
Cluster observations of whistler mode ducts and banded chorus
Pickett, J. S.; Facskó, G.; Inan, U. S. +3 more
Bell et al. (2009) proposed that the source region for banded chorus consists of whistler mode ducts of depleted electron density (Ne) for upper band (UB) chorus for all wave normal angles ($\theta$) and ducts of either enhanced or depleted Ne for lower band (LB) chorus for small $\theta$ and $\theta$ near or greater than the…
Electromagnetic ion cyclotron waves in the helium branch induced by multiple electromagnetic ion cyclotron triggered emissions
Dandouras, Iannis; Omura, Yoshiharu; Shoji, Masafumi +3 more
Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the m…
Location of Saturn's northern infrared aurora determined from Cassini VIMS images
Brown, R. H.; Baines, K. H.; Dougherty, M. K. +6 more
The location of Saturn's northern infrared aurora is described in detail using 12 selected images acquired by Cassini VIMS during 2006-2008. Bright main oval arcs and prevalent polar features are displayed, which do not exhibit a preferred local time or spatial extent. The average equatorward limit of the aurora was determined using a best fit cir…