Titan's Atmospheric Temperatures, Winds, and Composition
Strobel, D. F.; Showalter, M. R.; Lellouch, E.; Irwin, P. G. J.; Teanby, N. A.; Orton, G. S.; Calcutt, S. B.; Bowles, N.; Taylor, F. W.; Spencer, J. R.; Spilker, L. J.; Pearl, J. C.; Flasar, F. M.; Bézard, B.; Ade, P.; Coustenis, A.; Fouchet, T.; Achterberg, R. K.; Jennings, D. E.; Nixon, C. A.; Vinatier, S.; Carlson, R. C.; Romani, P. N.; Courtin, R.; Ferrari, C.; Owen, T. C.; Samuelson, R. E.; Simon-Miller, A. A.; Barucci, A.; Read, P. L.; Bjoraker, G. L.; Marten, A.; Conrath, B. J.; Kunde, V. G.; Brasunas, J.; Segura, M. E.; Mamoutkine, A.; Gierasch, P. J.; Schinder, P. J.; Gautier, D.; Prangé, R.; Abbas, M. M.; Raulin, F.; Edgington, S.; Wishnow, E. H.
United States, France, United Kingdom
Abstract
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, temperatures in the stratosphere are 4 to 5 kelvin cooler than at the equator. The stratospheric mole fractions of methane and carbon monoxide are (1.6 +/- 0.5) × 10-2 and (4.5 +/- 1.5) × 10-5, respectively.