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…
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…
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…
The reflectance spectrum of Titan's surface at the Huygens landing site determined by the descent imager/spectral radiometer
Keller, H. U.; Schröder, S. E.
The descent imager/spectral radiometer aboard the Huygens probe successfully acquired images and spectra of the surface of Titan. To counter the effects of haze and atmospheric methane absorption it carried a surface science lamp to illuminate the surface just before landing. We reconstruct the reflectance spectrum of the landing site in the 500-1…
Influence of high abundances of aerosols on the electrical conductivity of the Titan atmosphere
Whitten, R. C.; Borucki, W. J.
Observations of optical depth and scattering by instrumentation onboard the Huygens probe have been used by Tomasko et al. [Tomasko et al., 2005. Rain, winds and haze during Huygens probe's descent to Titan's surface. Nature 438 (8), 765-778] to deduce that the size and abundance of Titan aerosols could be nearly independent of altitude. Here we s…
New laboratory measurements of CH 4 in Titan's conditions and a reanalysis of the DISR near-surface spectra at the Huygens landing site
Lellouch, E.; Bézard, B.; Coustenis, A. +5 more
Laboratory spectra of methane-nitrogen mixtures have been recorded in the near-infrared range (1.0-1.65 µm) in conditions similar to Titan's near surface, to facilitate the interpretation of the DISR/DLIS (DISR - Descent Imager/Spectral Radiometer) spectra taken during the last phase of the descent of the Huygens Probe, when the surface was …
Titan's aerosols: Comparison between our model and DISR findings
Bar-Nun, A.; Dimitrov, V.; Tomasko, M.
Our model [Dimitrov, V., Bar-Nun, A., 1999. A model of energy dependent agglomeration of hydrocarbon aerosol particles and implication to Titan's aerosol. J. Aerosol. Sci. 30(1), 35-49] describes the experimentally found polymerization of C 2H 2 and HCN to form aerosol embryos, their growth and adherence to form various aeros…