Shape of N polar cap explained, 3D structure and history from SHARAD data |
Shape of N polar cap explained, 3D structure and history from SHARAD data |
May 27 2010, 11:39 AM
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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 |
Article from Science Daily with link to Nature paper:
http://www.sciencedaily.com/releases/2010/...00526134150.htm |
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May 28 2010, 03:01 PM
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#2
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Forum Contributor Group: Members Posts: 1372 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
It's cool to learn something new about Mars.
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May 28 2010, 06:49 PM
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#3
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Junior Member Group: Members Posts: 55 Joined: 6-March 10 From: Cincinnati, OH Member No.: 5246 |
The article says that the spiral troughs are due to erosion caused by katabatic winds that are deflected by the Coriolis force.
The problem is that the troughs spiral outward in an anti-Coriolis direction. i.e, They curve westward not eastward as would be expected. I wish I had access to the original paper. This seems to be an error in the article. Can anyone with access to paper elaborate? Tom |
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May 28 2010, 09:31 PM
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#4
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Senior Member Group: Members Posts: 1582 Joined: 14-October 05 From: Vermont Member No.: 530 |
They're anti-cyclonic, that is the high pressure is over the poles. The north pole looks the opposite of a hurricane in the northern hemisphere of earth. Seems to make sense to me.
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May 29 2010, 12:52 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 |
A cold, dense air mass moving downslope (and southward) from the pole should create a katabatic wind that curves to the west (an easterly wind).
If these winds are responsible for eroding the troughs, then you'd expect the troughs to curve to the west as viewed by an observer at the pole looking south. Instead the troughs curve to the east. In other words, the swirl pattern viewed from space should look like a like a counterclockwise spinning cyclone, not the clockwise pattern actually seen. Tom |
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Jun 17 2010, 01:14 AM
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#6
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Senior Member Group: Members Posts: 1582 Joined: 14-October 05 From: Vermont Member No.: 530 |
A little more explication on this:
http://science.nasa.gov/science-news/scien...martianspirals/ Sounds like the winds are perpendicular to the gully direction? |
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Jun 17 2010, 02:12 PM
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#7
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Junior Member Group: Members Posts: 55 Joined: 6-March 10 From: Cincinnati, OH Member No.: 5246 |
A little more explication on this: http://science.nasa.gov/science-news/scien...martianspirals/ Sounds like the winds are perpendicular to the gully direction? Thanks. That explains more. Tom |
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