Elsevier

Earth and Planetary Science Letters

Volume 474, 15 September 2017, Pages 20-24
Earth and Planetary Science Letters

Surface roughness of Titan's hydrocarbon seas

https://doi.org/10.1016/j.epsl.2017.06.007Get rights and content
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Highlights

  • We estimate roughness for Titan's northern seas in the early summer.

  • Both vertical and horizontal roughness parameters are derived.

  • The surfaces are quiet and smooth, consistent with former radar observations.

  • Fields of wave activity might be transient or occur at local scales.

Abstract

We derive fields of solutions for the surface properties (roughness and permittivity) of the liquid hydrocarbon bodies Ligeia, Kraken and Punga Mare on Titan by applying the Radar Statistical Reconnaissance (RSR) technique to the Cassini RADAR observations in altimeter mode during the northern early summer. At the time of observation, Kraken and Ligeia were confined within root-mean-square heights of 1.5–2.5 mm (similar to wave heights of 6–10 mm), correlation lengths of 45–115 mm, and corresponding to effective slopes of 1.1–2.4°. The latter extends up to 3.6–4.9° if the rougher Punga is included. The lower bound of those ranges has to be considered if the composition of the seas is methane-dominant. These are the first measurements to simultaneously constrain both the vertical and horizontal roughness parameters of Titan's seas from the same observations. Our results are representative for the global properties of the sea-scaled portion of the studied tracks and suggest that quiet surfaces are a dominant trend over the seas during the northern early summer. Fields of rougher textures, if existent, might develop mainly over local patches and/or might not be sustained over significant periods of time.

Keywords

Titan
radar
roughness
waves

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