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G. Schubert (Dept. of Earth and Space Sci. and IGPP, UCLA), R.L. Walterscheid (The Aerospace Corp. and NOAAA/NESDIS at EUMETSAT)
The existence of multiple haze layers in Titan's upper atmosphere suggests that some physical mechanism concentrates aerosols into horizontally extensive and vertically confined regions. It is proposed here that the relevant mechanism could be the vertical transport of aerosol particles by Saturn 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. The strongly forced eastward propagating s=2 tide is killed in regions where it is Doppler shifted to small intrinsic frequency in the super-rotating atmospheric winds. Only the weakly forced westward propagating s=2 tide reaches high altitudes where its vertical wavelength is 0\/(100~\mathrm{km}) and it induces 0\/(100~\mathrm{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. However, this tide might produce some layering in the weaker winds below. Supported by the NASA Planetary Atmospheres Program.
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Bulletin of the American Astronomical Society, 37 #3
© 2004. The American Astronomical Soceity.