Search Publications
Cassini Radio Occultation Observations of Saturn's Ionosphere: Electron Density Profiles From 2005 to 2013
Withers, Paul; Dalba, P. A.; Moore, L. +2 more
A set of electron density profiles of Saturn's ionosphere acquired by Cassini radio occultations is archived at the NASA Planetary Data System. However, the reference surface that defines zero altitude in these profiles is unknown and appears to vary by 1,500 km at fixed latitude. These profiles are immensely valuable for addressing questions pert…
On Current Sheets and Associated Density Spikes in Titan's Ionosphere as Seen From Cassini
Edberg, Niklas J. T.; Vigren, Erik; Bertucci, Cesar +3 more
The Cassini spacecraft made in-situ measurements of Titan's plasma environment during 126 close encounters between 2004 and 2017. Here we report on observations from the Radio and Plasma Waves System/Langmuir probe instrument (RPWS/LP) from which we have observed, primarily on the outbound leg, a localized increase of the electron density by up to…
Magnetopause Dynamics at Saturn as Observed by Cassini
Allen, Robert C.; Mo, Wenli; Paranicas, Chris +2 more
The occurrence and impacts of magnetopause processes at outer planets, particularly magnetic reconnection and the Kelvin-Helmholtz instability (KHI), remains unresolved. From a list of 2,114 magnetopause crossings at Saturn spanning the full duration of the Cassini mission, magnetic field and low-energy plasma properties are analyzed for each cros…
Influence of Titan's Variable Electromagnetic Environment on the Global Distribution of Energetic Neutral Atoms
Simon, Sven; Tippens, Tyler; Liuzzo, Lucas
We combine the electromagnetic fields from a hybrid plasma model with a particle tracing tool to study the spatial distribution of energetic neutral atoms (ENAs) emitted from Titan's atmosphere when the moon is exposed to different magnetospheric upstream regimes. These ENAs are generated when energetic magnetospheric ions undergo charge exchange …
Observations of the First Harmonic of Saturn Kilometric Radiation During Cassini's Grand Finale
Lamy, Laurent; Fischer, Georg; Kurth, William S. +6 more
Clear first harmonic emissions of Saturn Kilometric Radiation are discovered during the Cassini Grand Finale orbits. Both ordinary (O) and extraordinary (X) mode fundamental emissions accompanied by X mode harmonics are observed. Analysis shows that the frequency ratio between the fundamental and harmonic emissions is 2.01 ± 0.08, and the harmonic…
The Response of Saturn's Dawn Field-Aligned Currents to Magnetospheric and Ring Current Conditions During Cassini's Proximal Orbits: Evidence for a Region 2 Response at Saturn
Dougherty, M. K.; Roussos, E.; Cowley, S. W. H. +3 more
Cassini's 2017 proximal orbits provided the opportunity to examine the auroral field-aligned currents in the northern hemisphere dawn sector in relation to wider magnetospheric conditions. We combine three recent studies to examine the response of the dawn region auroral field-aligned currents and the azimuthal ring currents to compressions and ex…
Detection of Equatorial Plasma Velocity Modulations Associated With Planetary Period Oscillations in Saturn's Magnetosphere
Wilson, R. J.; Cowley, S. W. H.; Provan, G. +1 more
We analyze a database of 8920 measurements of thermal ion vector velocities obtained by the Cassini CAPS/IMS instrument in the near-equatorial (±10° latitude) region of Saturn's magnetosphere in the radial range of 5.5-21.5 Saturn radii (RS) for the presence of modulations due to planetary period oscillations (PPOs). The data span 2004-…
Jupiter's Auroral Radio Emissions Observed by Cassini: Rotational Versus Solar Wind Control, and Components Identification
Cecconi, B.; Lamy, L.; Zarka, P. +5 more
Reanalyzing Cassini radio observations performed during Jupiter's flyby of 2000-2001, we study the internal (rotational) versus external (solar wind) control of Jupiter's radio emissions, from kilometer to decameter wavelengths, and the relations between the different auroral radio components. For that purpose, we build a database of the occurrenc…
Flux Transfer Events at a Reconnection Suppressed Magnetopause: Cassini Observations at Saturn
Coates, Andrew J.; Fuselier, Stephen A.; Slavin, James A. +5 more
We present the discovery of seven new flux transfer events (FTEs) at Saturn's dayside magnetopause by the Cassini spacecraft and analyze the observations of all eight known FTEs. We investigate how FTEs may differ at Saturn where the magnetopause conditions are likely to diamagnetically suppress magnetic reconnection from occurring. The measured i…
Empirical Selection of Auroral Kilometric Radiation During a Multipoint Remote Observation With Wind and Cassini
Jackman, C. M.; Bonnin, X.; Cecconi, B. +5 more
Auroral Kilometric Radiation (AKR) is terrestrial radio emission that originates in particle acceleration regions along magnetic field lines, coinciding with discrete auroral arcs. AKR viewing geometry is complex due to the confinement of the source regions to nightside local times (LTs) and the anisotropy of the beaming pattern, so observations a…