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Looking at pictures of Jupiter, there are many different colours and patterns. I imagine that the rotation has much to do with this, since there are horizontal "bands" across the planet along the direction of rotation.

If the rotation would slow down and eventually stop, would the atmosphere get mixed and even out over time until we could only see a fuzzy brown (?) color but no color shifts or other patterns on the surface?

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    $\begingroup$ @CarlWitthoft The OP can imagine as much as they like. Please refrain from telling someone off for not knowing precisely the thing they are asking about. $\endgroup$
    – Ingolifs
    Jan 29, 2020 at 8:23
  • $\begingroup$ @Ingolifs This is a technological site. As such, questions should be posed based on referenced data or the equivalent. If the OP had written "Do the atmospheric bands result from planetary rotation?" that would be a valid question. $\endgroup$ Jan 29, 2020 at 15:26

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They're often called jet streams, but the visible bands you see in Jupiter are probably more like Hadley cells. Convection currents that move heat from lower in the planet's surface to higher before cooling and circling back downward. The darker bands are rising warmer atmosphere, the lighter bands, made lighter in color by more ice, are falling.

https://en.wikipedia.org/wiki/Hadley_cell#/media/File:Earth_Global_Circulation_-_en.svg

https://en.wikipedia.org/wiki/Atmosphere_of_Jupiter#Zones,_belts_and_jets

Jupiter's fast rotation gives it several Hadley cells per hemisphere. By comparison, Earth has 3 and Venus has 1. Faster rotation and perhaps Jupiter's larger size as well creates more Hadley cells.

That said, if Jupiter didn't rotate, it would still have heat from below, rising and escaping. It would still shed temperature from below, because of internal heat.

What it might look like is a complicated question but I think a uniform brown is unlikely. It would still have regions of darker, warmer rising air and lighter more ice filled, colder falling air. Jupiter's bands aren't because it's atmosphere doesn't mix, it's because warm Jupiter air is a different color than cold more icy Jupiter air.

Also, no rotation effectively gives the planet a sun side and a night side. That would vary some depending on no rotation at all, vs a slow tidally locked rotation, but even so, the Sun side would be warmer. Jupiter's upper atmosphere is more driven by heat from below than heat from the Sun, but the Sun would still have an effect, especially if it only shone on one side of the planet.

I don't think we have a good sense of what non-rotating Jupiter type planet might look like. The upper atmosphere temperature would be a primary factor, but with no rotation, I think it would probably require some high level mathematical modeling to work out an answer.

Some kind of grand current might be possible, perhaps with patterns perhaps similar to the "Y" shape observable in UV in Venus' atmosphere, or perhaps an ocean current like pattern, but that's just speculation.

https://www.space.com/28835-venus-y-shape-mystery-solved.html

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    $\begingroup$ We do know now how Jupiters' poles look like, which satisfy the condition of 'nearly no rotation'. So I wouldn't claim we have no idea. The convective storms seen there surely would pop up throughout other non-rotating areas of the planet as well. $\endgroup$ Jan 28, 2020 at 22:43
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    $\begingroup$ Heck, we only have to wait a couple hundred million years for Jupiter to be tidal-locked :-) $\endgroup$ Jan 29, 2020 at 16:03
  • $\begingroup$ You could probably get a decent idea of what it would look like by numerically integrating the shallow-water equations. But I'll leave wrangling the (vector) spherical harmonics to someone else... $\endgroup$
    – user24157
    Jan 29, 2020 at 21:52

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