Titan's Atmospheric Temperatures, Winds, and Composition

  title={Titan's Atmospheric Temperatures, Winds, and Composition},
  author={F. Flasar and R. Achterberg and B. Conrath and P. Gierasch and V. Kunde and C. Nixon and G. Bjoraker and D. Jennings and P. Romani and A. Simon-Miller and B. B{\'e}zard and A. Coustenis and P. Irwin and N. Teanby and J. Brasunas and J. Pearl and M. Segura and R. Carlson and A. Mamoutkine and P. J. Schinder and A. Barucci and R. Courtin and T. Fouchet and D. Gautier and E. Lellouch and A. Marten and R. Prang{\'e} and S. Vinatier and D. Strobel and S. Calcutt and P. Read and F. Taylor and N. Bowles and R. Samuelson and G. Orton and L. Spilker and T. Owen and J. Spencer and M. Showalter and C. Ferrari and M. Abbas and F. Raulin and S. Edgington and P. Ade and E. Wishnow},
  pages={975 - 978}
Temperatures obtained from early Cassini infrared observations of Titan show a stratopause at an altitude of 310 kilometers (and 186 kelvin at 15°S). Stratospheric temperatures are coldest in the winter northern hemisphere, with zonal winds reaching 160 meters per second. The concentrations of several stratospheric organic compounds are enhanced at mid- and high northern latitudes, and the strong zonal winds may inhibit mixing between these latitudes and the rest of Titan. Above the south pole… Expand
The Evolution of Titan's Mid-Latitude Clouds
Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal that the horizontal structure, height, and optical depth of Titan's clouds are highly dynamic, suggesting that temperate clouds originate from circulation-induced convergence, in addition to a forcing at the surface associated with Saturn's tides, geology, and/or surface composition. Expand
The structure and dynamics of Titan's middle atmosphere
  • F. Flasar, R. Achterberg
  • Environmental Science, Biology
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2008
Cassini CIRS observations indicate that the stratosphere near 1 mbar is warmest at low latitudes, with the South Pole a few degrees colder and the North Pole approximately 20 K colder, which implies subsidence at the pole, which is consistent with the enhanced organics observed. Expand
Compositional evidence for Titan's stratospheric tilt
Abstract Five years of Cassini CIRS infrared spectra have been used to determine the tilt of Titan's stratospheric symmetry axis with respect to the solid body rotation axis. Measurements of HCNExpand
Horizontal structures and dynamics of Titan's thermosphere
[1] The Cassini Ion Neutral Mass Spectrometer (INMS) measures densities of gases including N2 and CH4 in situ in Titan's upper atmosphere. We have used data from 13 targeted flybys of Titan (T5–T32)Expand
Evidence for a Polar Ethane Cloud on Titan
Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal the presence of a vast tropospheric cloud on Titan and derived characteristics indicate that this cloud is composed of ethane and forms as a result of stratospheric subsidence and the particularly cool conditions near the moon's north pole. Expand
Dissipation of Titan's north polar cloud at northern spring equinox
Abstract Saturn's Moon Titan has a thick atmosphere with a meteorological cycle. We report on the evolution of the giant cloud system covering its north pole using observations acquired by the VisualExpand
Temporal Variations of Titan's Middle-Atmospheric Temperatures from 2004 to 2009 Observed by Cassini/CIRS
We use five and one-half years of limb- and nadir-viewing temperature mapping observations by the Composite Infrared Radiometer-Spectrometer (CIRS) on the Cassini Saturn orbiter, taken between JulyExpand
Titan's stratospheric zonal wind, temperature, and ethane abundance a year prior to Huygens insertion
[1] Saturn's satellite, Titan, may have stratospheric winds up to ∼210 m/s, circling Titan in ∼1 terrestrial day compared to its 16-day rotation. Theoretical models explaining such super-rotatingExpand
Radiance from the surface of Titan can be detected from space through a spectral window of low opacity in the thermal infrared at 19 μm (530 cm–1). By combining Composite Infrared SpectrometerExpand
The distribution of methane in Titan’s stratosphere from Cassini/CIRS observations
Abstract Cassini/CIRS spectra in the far- and mid-infrared region are used to determine the abundance of methane in Titan’s lower stratosphere and investigate its distribution with latitude. The CIRSExpand


Titan's atmosphere: temperature and dynamics
In the lower atmosphere of Titan IR brightness temperatures exhibit meridional contrast \[lsims]3 K. Seasonal variations are absent because of the large radiative time constant. In the upperExpand
Temperatures, Winds, and Composition in the Saturnian System
Diurnal surface temperature variations on Phoebe suggest a more porous regolith than on the jovian satellites, and Saturn's ring temperatures have radial variations down to the smallest scale resolved (100 kilometers). Expand
Titan's stratospheric temperature asymmetry: a radiative origin?
The radiative budget of Titan's stratosphere is investigated, using two selections of Voyager IRIS spectra recorded at symmetric northern and southern latitudes, to find that the latitudinal variation in gas and haze composition may be sufficient to explain the entire temperature asymmetry observed. Expand
Titan's stratospheric temperatures: A case for dynamical inertia?
Temperatures between the 1- and 0.4-mbar barometric pressure levels of Titan's atmospere have been retrieved from Voyager IRIS spectral radiances in the λ4-band of CH4. They exhibit a hemisphericExpand
Seasonal Variations of Titan's Atmospheric Composition
In order to investigate seasonal variations of the composition of Titan’s low stratosphere, we developed a two-dimensional (latitude‐ altitude) photochemical and transport model. Large-scaleExpand
Seasonal variation of Titan's stratospheric ethylene (C2H4) observed ☆
Abstract All previous observations of seasonal change on Titan have been of physical phenomena such as clouds and haze. We present here the first observational evidence of chemical change in Titan'sExpand
Titan's stratospheric composition driven by condensation and dynamics
[1] Atmospheric transport of chemical compounds and organic haze in the stratosphere of Titan is investigated with an axisymmetric general circulation model. It has been shown previously that theExpand
Titan's Atmosphere from Voyager Infrared Observations: IV. Latitudinal Variations of Temperature and Composition
Abstract We have analyzed nine Voyager 1 infrared spectral averages covering Titan's disk from 53°S to 70°N. By use of radiative transfer modeling we have determined the thermal profiles and meanExpand
The Structure of Titan's Stratosphere from the 28 Sgr Occultation
Abstract A dozen lightcurves obtrained during the ground-based observations of the occulation of 28 Sgr by Titan (3 July 1989) are reanalyzed. Profiles of density and temperature between altitudeExpand
Numerical simulation of the general circulation of the atmosphere of Titan.
Diagnostics of the simulated atmospheric circulation underlying the importance of the seasonal cycle and a tentative explanation for the creation and maintenance of the atmospheric superrotation based on a careful angular momentum budget are presented. Expand