Water and CO2 on Mars, intrerrelated phase change processes. |
Water and CO2 on Mars, intrerrelated phase change processes. |
Sep 22 2010, 10:30 PM
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#1
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
I think this will be of interest: http://www.sciencedaily.com/releases/2010/...00922124546.htm
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Sep 23 2010, 10:47 AM
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#2
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Junior Member Group: Members Posts: 55 Joined: 6-March 10 From: Cincinnati, OH Member No.: 5246 |
Some interesting dynamics going on here. If some of the CO2 ice gets temporarily covered each season by a thin layer of water ice, you might expect some areas (shaded areas in north-facing troughs?) to retain CO2 ice throughout the summer and become permanently incorporated into the North Pole Layered Deposits (NPLD). This suggests that the NPLD might contain significant amounts of CO2 ice, but I don't think the spectroscopic evidence indicates this (?). Hmm.
Tom |
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Sep 23 2010, 11:40 AM
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#3
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Senior Member Group: Moderator Posts: 2785 Joined: 10-November 06 From: Pasadena, CA Member No.: 1345 |
The thin layer of ice might spectroscopically mask the CO2. (Like as a paint covering).
I wonder if something that penetrates deeper might notice a change, like a RADAR experiment that could measure dielectric constant. (At 0 C, dielectric constant of H2O = 88, CO2 = 1.6. [reference list here]) -------------------- Some higher resolution images available at my photostream: http://www.flickr.com/photos/31678681@N07/
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Sep 23 2010, 12:37 PM
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#4
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Junior Member Group: Members Posts: 55 Joined: 6-March 10 From: Cincinnati, OH Member No.: 5246 |
The thin layer of ice might spectroscopically mask the CO2. (Like as a paint covering). I bet it does. If there's a lot of CO2 squestered in the caps, what are the implications for past climate conditions? I wonder if there's enough there to increase the average surface pressure significantly if released. I suspect not...but... Tom |
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Sep 23 2010, 12:48 PM
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#5
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Junior Member Group: Members Posts: 55 Joined: 6-March 10 From: Cincinnati, OH Member No.: 5246 |
Update: I just looked at Shane Byrne's review article in Annual Review of Earth and Planetary Science (2009). He says (p. 541) that "buried CO2 ice and CO2 clathrate hydrate have been eliminated as important components [of the NPLD] on the basis of thermal and mechanical strength arguments. He cites paper by Mellon (1996) and Nye et. a, (2000).
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Oct 20 2010, 12:26 AM
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#6
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Junior Member Group: Members Posts: 59 Joined: 12-November 09 Member No.: 5039 |
Subsurface temperatures quickly approach year-average temps: at ~20 meters, temperature barely changes. I think even at Mars poles year-average temperature is above CO2 sublimation point.
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