Search Publications

Winter Weakening of Titan's Stratospheric Polar Vortices

Toigo, A. D.; Teanby, N. A.; Newman, C. E. +3 more

Polar vortices are a prominent feature in Titan's stratosphere. The Cassini mission has provided a detailed view of the breakdown of the northern polar vortex and formation of the southern vortex, but the mission did not observe the full annual cycle of the evolution of the vortices. Here we use a TitanWRF general circulation model simulation of a…

Observations and Modeling of the Opposition Surges of the Icy Moons of Saturn Based on Cassini Visual Infrared Mapping Spectrometer Data

Buratti, B. J.; Hendrix, A. R.; Dalba, P. A. +5 more

Observations of the opposition surges on the main moons of Saturn (Mimas, Enceladus, Tethys, Dione, Rhea, and Iapetus) during Cassini's prime and extended missions are reduced and analyzed. The main data set comes from the Visual Infrared Mapping Spectrometer (VIMS) with wavelength coverage in the visible and near-infrared out to 3.60 µm, co…

Titan Stratospheric Haze Bands Observed in Cassini VIMS as Tracers of Meridional Circulation

Le Mouélic, S.; Rodriguez, S.; Sotin, C. +9 more

We analyzed Cassini data to derive the nature and evolution of circumglobal annuli observed in the stratosphere of Titan, Saturn's largest moon. The annuli were observed between 2004 and 2017 in data acquired by the Visual and Infrared Mapping Spectrometer on board the Cassini spacecraft. We observed a north polar annulus, an equatorial annulus, a…

Identifying Shadowing Signatures of C Ring Ringlets and Plateaus in Cassini Data from Saturn's Ionosphere

Vigren, Erik; Wahlund, Jan-Erik; Dreyer, Joshua +5 more

For orbits 288 and 292 of Cassini's Grand Finale, clear dips (sharp and narrow decreases) are visible in the ${{\rm{H}}}_{2}^{+}$ densities measured by the Ion and Neutral Mass Spectrometer (INMS). In 2017, the southern hemisphere of Saturn was shadowed by its rings and the substructures within. Tracing a path of the solar photons through the ring…

Seasonal Variations of Chemical Species and Haze in Titan's Upper Atmosphere

Fan, Siteng; Zhao, Daniel; Li, Cheng +3 more

Seasonal variation is significant in Titan's atmosphere owing to the large change of solar insolation resulting from Titan's 26.7° axial tilt relative to the plane of Saturn's orbit. Here we present an investigation of hydrocarbon and nitrile species in Titan's upper atmosphere at 400-1200 km, which includes the mesosphere and the lower thermosphe…

Dione's Thermal Inertia and Bolometric Bond Albedo Derived from Cassini/CIRS Observations of Solar Eclipse Ingress

Spencer, John R.; Howett, Carly J. A.

On 2010 May 18 Cassini's Composite Infrared Spectrometer (CIRS) observed Dione's leading hemisphere as its surface went into solar eclipse. Surface temperatures derived from each of CIRS' focal plane 3 (FP3, 600-1100 cm^-1) show a rapid decrease in Dione's surface temperature upon eclipse ingress. This change was compared to the model su…