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The atmosphere of Venus contains strong winds and is said to have a "super rotation" because the atmosphere (above a certain altitude) moves faster than what the ground does.

No one can disagree with the fact that the atmosphere moves faster than the ground at most altitudes. However, does the wind pattern literally rotate around the planet as the common wording implies? Or... does the atmosphere actually zig-zag from the day side to the night side (nonetheless faster than the ground movement), making the common description of "super rotation" a popular misconception? This is one case where I think that pictures ask the question better than text:

True Rotation

This is just one example. I think that the underlying notion is pretty obvious.

True Rotation

Zig Zag

This illustration comes from the Wikimedia Commons. It is, in fact, the most detailed illustration of the wind pattern on Venus that Wikipedia has. In spite of my trying, I can not find any evidence that the image was ever depreciated and removed from the relevant English page due to changing science, or the less relevant page for that matter. The image timestamp actually predates the corresponding article, which casts suspicion on the accuracy of those time stamps in general. Overall, the use history is very unclear to me. Also note, here is a site which might be the source and contains the diagram in English.

Venus wind currents

Please do not mistake this illustration for the one currently displayed on the Wikipedia page, since that one shows Meridional flow only. This question is strictly about zonal flow.

Mechanistically, I can understand the Zig Zag a lot better since the sun's heat is the driving force. If the pattern was a true rotating, then where is the driving force coming from? There's not choked flow coming from the cold side or anything like that, so the driving force from the expansion of the gas due to heating can't exert a net-force along latitude lines. But it's difficult to track down the science, since I can't tell who is just incorrectly recounting something they heard from somewhere else, and who actually understands.

So which is it? Does the wind pattern really rotate, or does it just zig zag?

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I think this is the closest to a true answer I've seen:

http://ase.tufts.edu/cosmos/print_images.asp?id=7

superrotation

Both the image and the explanation seem to suggest a super-rotation that exists above a lower layer of Hadley cells. Even the original image that I posted depicted both things on the same image, although it wasn't clear what the relative locations were. I also read somewhere (can not remember where now) that Hadley cells are what give momentum to sustain the super rotation. If I imagine some kind of asymmetry at the boundary between the two (not difficult to do), then it can make sense.

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    $\begingroup$ I can't imagine that assymmetry. Do you know of any analogy or similar example? $\endgroup$ – kim holder Apr 15 '15 at 13:45
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If Venus were not rotating, then the incident sunlight would heat the upper atmosphere, and the Hadley cells would transport the heat away uniformly in all directions. However, because Venus is rotating, the flow at the top of the Hadley cells ahead of the subsolar point is traveling faster than the flow behind the subsolar point. This differential in speed results in an acceleration in the direction of Venus' rotation, with the result of the upper atmosphere rotating faster than the planet. Thus, the Hadley cells are effectively a lubricating layer between the planet and upper atmosphere which, en masse, must be considered a separate, enclosing body that is rotating faster than the planet itself.

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