nprev
Feb 1 2007, 11:22 PM
Aha! Now THIS is something to watch long-term...be interesting to see what it does as equinox approaches (& whether another one begins forming @ the South Pole).
ngunn
Feb 2 2007, 10:06 AM
Fantastic! I'm beginning to believe that it's really raining underneath.
remcook
Feb 2 2007, 10:19 AM
Judging from the press release, they seem to think it's tropospheric. I'm not so sure.
I'd like to see how different it is from the ethane cloud of Griffith et al.
Webscientist
Feb 3 2007, 10:26 PM
Griffith had reported the clouds were made of ethane. Here, they say it's made of ethane,methane and other hydrocarbon compounds. That implies that the lakes are most likely made of ethane or methane.
They add that the presence of the cloud is predicted by the atmospheric circulation model of Titan. How do you explain it? why lakes in high northern latitudes? and also why lakes in Titan's south pole?
http://www.titanexploration.com
remcook
Feb 4 2007, 04:53 PM
The clouds are predicted based on circulation and temperature. First of all, the north is very cold now, as it is winter there, and there is lots of cooling from gases (gases are enriched in the orth compared to anywhere else) that emit infrared radiation.
Then, there is a large downward movement of atmosphere in the north (opposed to the south, where there is upward movement). Because most molecules in Titan's atmosphere are produced at high altitudes by photochemistry, these gases are enriched at higher altitudes. The downward motion brings down the enriched 'air' to where temperatures are colder. This causes condensation (cloud formation). This is the proposed cloud formation process for stratospheric clouds like the ethane cloud of Griffith et al. The clouds produce rain, which would give lakes. In the south, this process happened a few years ago. Some lakes may be left over from this. Also, in the south there are these tropospheric storms that Cassini saw when it arrived.