Search Publications
Field-Aligned Currents in Saturn's Magnetosphere: Observations From the F-Ring Orbits
Dougherty, M. K.; Cowley, S. W. H.; Bunce, E. J. +3 more
We investigate the azimuthal magnetic field signatures associated with high-latitude field-aligned currents observed during Cassini's F-ring orbits (October 2016-April 2017). The overall ionospheric meridional current profiles in the northern and southern hemispheres, that is, the regions poleward and equatorward of the field-aligned currents, dif…
Multispacecraft Observations of Tailward Propagation of Transient Foreshock Perturbations to Midtail Magnetosheath
Wang, Chih-Ping; Liu, Terry Z.; Masson, Arnaud +1 more
We present three events from multiple spacecraft observations to show that a dayside transient foreshock perturbation associated with an interplanetary magnetic field directional discontinuity can propagate in the midtail magnetosheath and affect the magnetopause. In the first event, perturbations in density and flow were first observed in the day…
Recurrent Magnetic Dipolarization at Saturn: Revealed by Cassini
Coates, A. J.; Krupp, N.; Dougherty, M. K. +17 more
Planetary magnetospheres receive plasma and energy from the Sun or moons of planets and consequently stretch magnetic field lines. The process may last for varied timescales at different planets. From time to time, energy is rapidly released in the magnetosphere and subsequently precipitated into the ionosphere and upper atmosphere. Usually, this …
Monte Carlo Simulations of the Interaction of Fast Proton and Hydrogen Atoms With the Martian Atmosphere and Comparison With In Situ Measurements
Gérard, J. -C.; Hubert, B.; Shematovich, V. I. +1 more
We present model results of the interaction of proton and hydrogen atom precipitation with the Martian atmosphere. We use a kinetic Monte Carlo model developed earlier for the analysis of the Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) Mars Express data. With the availability of Mars Atmosphere and Volatile Evolution Mission in situ m…
Statistical Planetary Period Oscillation Signatures in Saturn's UV Auroral Intensity
Badman, S. V.; Cowley, S. W. H.; Provan, G. +3 more
Saturn's auroral emissions are a good measure of field-aligned current (FAC) systems in the planet's magnetospheric environment. Previous studies based on magnetic field data have identified current systems rotating with the planetary period oscillations (PPOs) in both hemispheres, superimposed onto the local time-invariant current system producin…
Precipitation of Hydrogen Energetic Neutral Atoms at the Upper Atmosphere of Mars
Kallio, E.; Barabash, S.; Futaana, Y. +3 more
We study the properties of neutral hydrogen atoms precipitating onto the upper atmosphere of Mars. Energetic neutral atoms (ENAs) are produced by the charge exchange process between protons of solar wind (both upstream and shocked) as well as planetary origins and the Martian exospheric neutrals. Using a global hybrid plasma model for Mars-solar w…
Mars Initial Reference Ionosphere (MIRI) Model: Updates and Validations Using MAVEN, MEX, and MRO Data Sets
Withers, Paul; Mayyasi, Majd; Mendillo, Michael +7 more
The Mars Initial Reference Ionosphere (MIRI) model is a semiempirical formulation designed to provide climatological estimates of key parameters of the Martian ionosphere. For the new MIRI-2018 version, an expanded database is used from the Mars Express/Mars Advanced Radar for Subsurface and Ionosphere Sounding/Active Ionospheric Sounding (MEX/MAR…
The Detached Auroras Induced by the Solar Wind Pressure Enhancement in Both Hemispheres From Imaging and In Situ Particle Observations
Zhou, Su; Luan, Xiaoli; Søraas, Finn +2 more
This paper presents simultaneous detached proton auroras that appeared in both hemispheres at 11:06 UT, 08 March 2012, just 2 min after a sudden solar wind pressure enhancement ( 11:04 UT) hit the Earth. They were observed under northward interplanetary magnetic field Bz condition and during the recovery phase of a moderate geomagnetic storm. In t…
Evolution of the Auroral Signatures of Jupiter's Magnetospheric Injections
Roussos, E.; Paranicas, C.; Bonfond, B. +3 more
Auroral emissions equatorward of the main emission at Jupiter are suggested to reflect the dynamics of the plasma in the middle magnetosphere. Here we examine the motion of the auroral signatures of magnetospheric injections appearing in Hubble Space Telescope (HST) images. Our results suggest that the injected plasma moves planetward and lags beh…
The Influence of Solar Wind and Geomagnetic Indices on Lower Band Chorus Emissions in the Inner Magnetosphere
Krasnoselskikh, V.; Walker, S. N.; Balikhin, M. A. +2 more
Statistical wave models, describing the distribution of wave amplitudes as a function of location, geomagnetic activity, and other parameters, are needed as the basis to describe the wave-particle interactions within numerical models of the radiation belts. In this study, we widen the scope of the statistical wave models by investigating which of …