Search Publications
Coupling photochemistry with haze formation in Titan's atmosphere, Part II: Results and validation with Cassini/Huygens data
Coustenis, A.; Lavvas, P. P.; Vardavas, I. M.
The new one-dimensional radiative-convective/photochemical/microphysical model described in Part I is applied to the study of Titan's atmospheric processes that lead to haze formation. Our model generates the haze structure from the gaseous species photochemistry. Model results are presented for the species vertical concentration profiles, haze fo…
A model of Titan's aerosols based on measurements made inside the atmosphere
Tomasko, M. G.; Doose, L.; Engel, S. +5 more
The descent imager/spectral radiometer (DISR) instrument aboard the Huygens probe into the atmosphere of Titan measured the brightness of sunlight using a complement of spectrometers, photometers, and cameras that covered the spectral range from 350 to 1600 nm, looked both upward and downward, and made measurements at altitudes from 150 km to the …
Coupling photochemistry with haze formation in Titan's atmosphere, Part I: Model description
Coustenis, A.; Lavvas, P. P.; Vardavas, I. M.
We introduce a new 1D coupled Radiative/Convective-Photochemical-Microphysical model for a planetary atmosphere and apply it to Titan. The model incorporates detailed radiation transfer calculations for the description of the shortwave and longwave fluxes which provide the vertical structure of the radiation field and temperature profile. These ar…
Fluvial erosion and post-erosional processes on Titan
Sotin, Christophe; Barnes, Jason W.; Rodriguez, Sebastien +16 more
The surface of Titan has been revealed by Cassini observations in the infrared and radar wavelength ranges as well as locally by the Huygens lander instruments. Sand seas, recently discovered lakes, distinct landscapes and dendritic erosion patterns indicate dynamic surface processes. This study focus on erosional and depositional features that ca…
The drying of Titan's dunes: Titan's methane hydrology and its impact on atmospheric circulation
Mitchell, Jonathan L.
We explore the effect of a finite reservoir of methane on Titan's atmospheric circulation, precipitation patterns, and surface methane content. We develop a soil model that accounts for the methane cycle in the surface-atmosphere system, and we implement this surface model in a two-dimensional model of the Titan's atmosphere. Seasonal oscillations…
Heat balance in Titan's atmosphere
Tomasko, M. G.; Bézard, B.; Doose, L. +3 more
The recent measurements of the vertical distribution and optical properties of haze aerosols as well as of the absorption coefficients for methane at long paths and cold temperatures by the Huygens entry probe of Titan permit the computation of the solar heating rate on Titan with greater certainty than heretofore. We use the haze model derived fr…
Sequestration of Ethane in the Cryovolcanic Subsurface of Titan
Mousis, Olivier; Schmitt, Bernard
Saturn's largest satellite, Titan, has a thick atmosphere dominated by nitrogen and methane. The dense orange-brown smog hiding the satellite's surface is produced by photochemical reactions of methane, nitrogen, and their dissociation products with solar ultraviolet, which lead primarily to the formation of ethane and heavier hydrocarbons. In the…
Diagnostics of Titan's stratospheric dynamics using Cassini/CIRS data and the 2-dimensional IPSL circulation model
Teanby, N. A.; Bézard, B.; Lebonnois, S. +6 more
The dynamics of Titan's stratosphere is discussed in this study, based on a comparison between observations by the CIRS instrument on board the Cassini spacecraft, and results of the 2-dimensional circulation model developed at the Institute Pierre-Simon Laplace, available at http://www.lmd.jussieu.fr/titanDbase [Rannou, P., Lebonnois, S., Hourdin…
Measurements of methane absorption by the descent imager/spectral radiometer (DISR) during its descent through Titan's atmosphere
Tomasko, M. G.; Bézard, B.; Doose, L. +2 more
New low-temperature methane absorption coefficients pertinent to the Titan environment are presented as derived from the Huygens DISR spectral measurements combined with the in-situ measurements of the methane gas abundance profile measured by the Huygens Gas Chromatograph/Mass Spectrometer (GCMS). The visible and near-infrared spectrometers of th…
The properties of Titan's surface at the Huygens landing site from DISR observations
Keller, H. U.; Küppers, M.; Schröder, S. E. +3 more
The descent imager/spectral radiometer (DISR) onboard the Huygens probe investigated the radiation balance inside Titan's atmosphere and took hundreds of images and spectra of the ground during the descent. The scattering of the aerosols in the atmosphere and the absorption by methane strongly influence the irradiation reaching the surface and the…