Experimental simulations of CH 4 evaporation on Titan

• Published in: Geophysical research letters 2012-12, Vol.39 (23)
• Main Authors: Luspay‐Kuti, A., Chevrier, V. F., Wasiak, F. C., Roe, L. A., Welivitiya, W. D. D. P., Cornet, T., Singh, S., Rivera‐Valentin, E. G.
• Format: Article
• Language: English
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2012GL054003

We present the first experimental results on the evaporation of liquid CH 4 under simulated Titan surface conditions similar to those observed at the Huygens landing site. An average evaporation rate of (3.1 ± 0.6) × 10 −4 kg s −1 m −2 at 94 K and 1.5 bar was measured. While our results are generally higher than previous models based on energy balance, they show an excellent match with a theoretical mass transfer approach. Indeed, we find that evaporation in the Titan environmental chamber is predominantly diffusion driven and affected by the buoyancy of lighter CH 4 in the heavier N 2 atmosphere. After correcting for the difference in gravity of Earth and Titan, the resulting evaporation rate is (1.6 ± 0.3) × 10 −4 kg s −1 m −2 (or 1.13 ± 0.3 mm hr −1 ). Using our experimental evaporation rates, we determine that the low‐latitude storm recently observed by Cassini ISS would have resulted in a maximum evaporated mass of (5.4 ± 1.2) × 10 10 kg of CH 4 equivalent to a 2.4 ± 0.5 m thick layer over 80 days. Based on our results, a sufficient amount of CH 4 can accumulate in the otherwise arid equatorial regions to produce transient ponds and liquid flows. First simulation of liquid hydrocarbons under Titan conditions The evaporation rate of liquid methane has been experimentally determined Methane can form transient ponds during equatorial storms