Wave constraints for Titan's Jingpo Lacus and Kraken Mare from VIMS specular reflection lightcurves

Jason W. Barnes, Jason M. Soderblom, Robert H. Brown, Laurence A. Soderblom, Katrin Stephan, Ralf Jaumann, Stéphane Le Mouélic, Sebastien Rodriguez, Christophe Sotin, Bonnie J. Buratti, Kevin H. Baines, Roger N. Clark, Philip D. Nicholson

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Stephan et al. (Stephan, K. et al. [2010]. Geophys. Res. Lett. 37, 7104-+.) first saw the glint of sunlight specularly reflected off of Titan's lakes. We develop a quantitative model for analyzing the photometric lightcurve generated during a flyby in which the specularly reflected light flux depends on the fraction of the solar specular footprint that is covered by liquid. We allow for surface waves that spread out the geographic specular intensity distribution. Applying the model to the VIMS T58 observations shows that the waves on Jingpo Lacus must have slopes of no greater than 0.15°, two orders of magnitude flatter than waves on Earth's oceans. Combining the model with theoretical estimates of the intensity of the specular reflection allows a tighter constraint on the waves: <0.05° Residual specular signal while the specular point lies on land implies that either the land is wetted, the wave slope distribution is non-Gaussian, or that 5% of the land off the southwest edge of Jingpo Lacus is covered in puddles. Another specular sequence off of Kraken Mare acquired during Cassini's T59 flyby shows rapid flux changes that the static model cannot reproduce. Points just 1. min apart vary in flux by more than a factor of two. The present dataset does not uniquely determine the mechanism causing these rapid changes. We suggest that changing wind conditions, kilometer-wavelength waves, or moving clouds could account for the variability. Future specular observations should be designed with a fast cadence, at least 6 points per minute, in order to differentiate between these hypotheses. Such new data will further constrain the nature of Titan's lakes and their interactions with Titan's atmosphere.

Original languageEnglish (US)
Pages (from-to)722-731
Number of pages10
JournalIcarus
Volume211
Issue number1
DOIs
StatePublished - Jan 2011

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specular reflection
Titan
lakes
glint
slopes
Titan atmosphere
static models
lake
footprints
sunlight
footprint
surface wave
surface waves
oceans
wavelength
liquid
atmosphere
ocean
estimates
liquids

Keywords

  • Photometry
  • Satellites, surfaces
  • Titan

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Barnes, J. W., Soderblom, J. M., Brown, R. H., Soderblom, L. A., Stephan, K., Jaumann, R., ... Nicholson, P. D. (2011). Wave constraints for Titan's Jingpo Lacus and Kraken Mare from VIMS specular reflection lightcurves. Icarus, 211(1), 722-731. https://doi.org/10.1016/j.icarus.2010.09.022

Wave constraints for Titan's Jingpo Lacus and Kraken Mare from VIMS specular reflection lightcurves. / Barnes, Jason W.; Soderblom, Jason M.; Brown, Robert H.; Soderblom, Laurence A.; Stephan, Katrin; Jaumann, Ralf; Mouélic, Stéphane Le; Rodriguez, Sebastien; Sotin, Christophe; Buratti, Bonnie J.; Baines, Kevin H.; Clark, Roger N.; Nicholson, Philip D.

In: Icarus, Vol. 211, No. 1, 01.2011, p. 722-731.

Research output: Contribution to journalArticle

Barnes, JW, Soderblom, JM, Brown, RH, Soderblom, LA, Stephan, K, Jaumann, R, Mouélic, SL, Rodriguez, S, Sotin, C, Buratti, BJ, Baines, KH, Clark, RN & Nicholson, PD 2011, 'Wave constraints for Titan's Jingpo Lacus and Kraken Mare from VIMS specular reflection lightcurves', Icarus, vol. 211, no. 1, pp. 722-731. https://doi.org/10.1016/j.icarus.2010.09.022
Barnes, Jason W. ; Soderblom, Jason M. ; Brown, Robert H. ; Soderblom, Laurence A. ; Stephan, Katrin ; Jaumann, Ralf ; Mouélic, Stéphane Le ; Rodriguez, Sebastien ; Sotin, Christophe ; Buratti, Bonnie J. ; Baines, Kevin H. ; Clark, Roger N. ; Nicholson, Philip D. / Wave constraints for Titan's Jingpo Lacus and Kraken Mare from VIMS specular reflection lightcurves. In: Icarus. 2011 ; Vol. 211, No. 1. pp. 722-731.
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