HR: 1340h
AN: P33C-0253    [Abstracts]
TI: A Tidal Explanation for the Titan Haze Layers
AU: Walterscheid, R L
EM: Richard.Walterscheid@eumetsat.int
AF: Space Program Operations Office, The Aerospace Corporation, PO Box 92957, El Segundo, CA 90009-2957 United States
AU: Walterscheid, R L
EM: Richard.Walterscheid@eumetsat.int
AF: Presently assigned to NOAAA/NESDIS at EUMETSAT, EUMETSAT, Darmstadt, D-64295 Germany
AU: * Schubert, G
EM: schubert@ucla.edu
AF: Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 595 Charles E. Young Drive East, Los Angeles, CA 90095-1567 United States
AB: The existence of multiple haze layers in Titan's upper atmosphere suggests that some physical mechanism concentrates aerosols into horizontally extensive and vertically connected regions. It is proposed here that the relevant mechanism could be the vertical transport of aerosol particles by Saturn's gravitational tides propagating energy upward through Titan's atmosphere. A quantitative analysis of the atmospheric gravitational tides shows that the winds in Titan's atmosphere strongly influence which tidal components could reach the high altitudes of the multiple haze layers. For a model of Titan's superrotating winds based on Doppler tracking of the Huygens probe the strongly forced eastward propagating s=2 tide is killed in regions where it is Doppler shifted to small intrinsic frequency. Only the weakly forced westward propagating s =2 tide reaches high altitudes where its vertical wavelength is O(100~km) and it induces O(100~m) vertical displacements of the atmosphere. The s=0 tide is strongly forced, but it dies in the strong high altitude winds, where its vertical wavelength becomes very short and it is strongly damped by scale-dependent diffusion. We also performed calculations for other wind models that might reflect the global wind system and find that the s=0 tide might produce some layering where moderate westward winds occur. The s=2 eastward tide might produce significant layering when the minimum eastward wind is strong enough to avoid Doppler shifting this tide to very small frequencies, but most likely the tide would be confined to low latitudes.
DE: 5405 Atmospheres (0343, 1060)
DE: 6281 Titan
SC: Planetary Sciences [P]
MN: Fall Meeting 2005