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Speed of sound measurements and the methane abundance in Titan's atmosphere

Hagermann, A.; Rosenberg, P. D.; Towner, M. C.; Garry, J. R. C.; Svedhem, H.; Leese, M. R.; Hathi, B.; Lorenz, R. D. and Zarnecki, J. C. (2007). Speed of sound measurements and the methane abundance in Titan's atmosphere. Icarus, 189(2) pp. 538–543.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1016/j.icarus.2007.02.004
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Abstract

Aboard the Huygens probe, which descended through Titan's atmosphere in January 2005, was the Surface Science Package (SSP), a set of 9 sensors, including a speed-of-sound sensor. We present the first detailed description of the SSP speed of sound measurements and report constraints on the methane content in Titan's lower atmosphere based on these measurements. After a careful calibration and subsequent Bayesian analysis, our measurements yield a most likely methane fraction in Titan's lower atmosphere of approximately 2% at 10 km, increasing to 3.5% at lower altitudes, based on a binary composition. Our data show that any large scale variation of methane within the lower 11 km of Titan's atmosphere is unlikely. Within experimental and theoretical uncertainties, our results are compatible with earlier estimates obtained from the GCMS experiment [Niemann, H.B., Atreya, S.K., Bauer, S.J., Carignan, G.R., Demick, J.E., Frost, R.L., Gautier, D., Haberman, J.A., Harpold, D.N., Hunten, D.M., Israel, G., Lunine, J.I., Kasprzak, W.T., Owen, T.C., Paulkovich, M., Raulin, F., Raaen, E., Way, S.H., 2005. Nature 438 (7069), 779–784].

Item Type: Journal Article
ISSN: 1090-2643
Keywords: Titan; Atmospheres, composition
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 8454
Depositing User: Users 2315 not found.
Date Deposited: 11 Jul 2007
Last Modified: 02 Dec 2010 20:01
URI: http://oro.open.ac.uk/id/eprint/8454
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