36th DPS Meeting, 8-12 November 2004
Session 30 Jupiter and Saturn: Composition, Structure, Dynamics
Oral, Thursday, November 11, 2004, 1:45-4:15pm, Clark

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[30.15] Coupling of pressure waves to clouds in the Jovian troposphere

P. Gaulme, B. Mosser (Observatoire de Paris)

The receipt for a successful study of the Jovian interior structure is given by the association of seismology and precise visible photometry. In this framework, the micro-satellite project Jovis, presented to the French space agency (Mosser et al. 2004), is for Jupiter a copy of what the Europen space mission COROT is for the stars (Baglin et al. 1998). The Jovian visible flux being dominated by the albedo map, an accurate analysis of the cloud response to a seismic wave is needed. Therefore, we have revisited the propagation of sound waves in the Jovian troposphere, in order to estimate how they affect the uppest clouds layer, composed of ammonia ice. First, considering Jupiter as a mirror, the expected variations of the reflected solar flux due to the smooth distorsions are about the ppm level for a 50 cm s-1 amplitude wave. Second, introducing thermodynamics, we determine the phase transitions induced by the waves in the clouds. These phase changes are linked to the ice particles growth, and limited by kinetics. A Mie model (Mishchenko et al 2002) associated to a simple radiation transfer model allows us to estimate that the final albedo fluctuations of the cloud perturbed by a seismic wave can reach the 70-ppm level. This gain of a factor 70 makes the phenomenon easier to observe and opens new prospectives for the seismic study of Jupiter : low amplitude modes, high degrees modes. \vspace{1cm}\\ Baglin et al. 1998. 185 IAU. Symp. pp. 301. Kyoto. \\ Mosser et al. 2004. SF2A-2004 pp. 257. EdP-Sciences, Les Ulis. \\ Mishchenko et al. 2002. Scatt. Abs. Em. Light Small Particles pp. 158-190. Cambridge University Press.

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Bulletin of the American Astronomical Society, 36 #4
© 2004. The American Astronomical Soceity.