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Stonius
05-03-2019, 04:12 PM
I've seen explanations that 'it's convection'. Sure, that explains the movement and the bands, but not why they manage to remain so distinct.

You can pour milk in coffee and it will eventually mix through the action of convection. Convection itself is not something that prevents different elements from mixing together, so what gives? That thing looks more like coloured oils on water.

Markus

Ukastronomer
05-03-2019, 07:18 PM
Who knows, ................. "eventually" they may

billdan
05-03-2019, 09:37 PM
I think its because they are at different altitudes relative to each other, so never interact. According to Wiki the Great Red Spot is 8Km higher than the clouds below. The white bands of storms are higher in altitude than the brown bands of storms.

gary
06-03-2019, 12:47 AM
I recollected reading this article a couple of years ago.
Apparently if you have a big garbage can and a rotating table you
can simulate Jupiter's atmosphere pretty well according to UCLA
geophysicists :-

http://newsroom.ucla.edu/releases/ucla-geophysicist-models-jupiters-swirling-winds

Paper at Nature (subscription required) -
https://www.nature.com/articles/nphys4001

Stonius
06-03-2019, 08:16 AM
Ah, thanks Gary, so it seems that the injection of turbulence from deep jets is the cause.

Thanks.

multiweb
06-03-2019, 10:14 AM
Jovian cows.

bojan
06-03-2019, 10:20 AM
The reason is the same for Earth weather never to stabilize: energy influx from Sun and from planet inside (more so in Jupiter case).

Stonius
06-03-2019, 10:50 AM
Jovine Bovines? :-D

Stonius
06-03-2019, 11:02 AM
It's not the movement or even the bands that I was questioning. To that extent, equivalent examples can be seen all over the solar system. The earth itself has convective bands corresponding to equatorial, temperate and polar weather systems, if I recall correctly. It's the lack of mixing of colours that confused me - there needs to be some form of continuous generation and destruction of those colours in order to keep them separate.

By way of example, say you could dye an entire tropical cyclone on earth pink. I don't think anyone really thinks that in 2 years there would still be distinct 'pink systems' in our atmosphere.

The upwelling jets in the example above makes sense to me in terms of supplying fresh phosphor (or whatever chemicals) to the surface, which then subsides due to convection before it has a chance to mix to uniformity.

I'll attach the sort of image that made me start thinking about all this.

Best,

Markus

bojan
06-03-2019, 12:40 PM
Different colurs mean different chemistry and/or different temperatures and other factors..

Chemistry of Jupiter atmosphere is very volatile, changing from place to place depending on insolation changes and internal heating as well.

I am fully aware my explanation is maybe even simplistic..

gary
06-03-2019, 01:34 PM
Hi Markus,

Your question about why Jupiter's clouds just don't all mix together into
a single homogeneous colour is a good one.

When I read it, it reminded me a of passage in a wonderful 1989 book
entitled "The Cuckoo’s Egg: Tracking a Spy Through the Maze of
Computer Espionage" (https://en.wikipedia.org/wiki/The_Cuckoo%27s_Egg) by Clifford Stoll (https://en.wikipedia.org/wiki/Clifford_Stoll).

The book is a personal account by Stoll in tracking a computer hacker who
was gaining access to a computer that he was managing at the Lawrence
Berkeley National Laboratory.

The book itself is one of the most entertaining reads of the 20th Century
and is highly recommended.

By profession, Stoll was an astronomer. In the book he provides a hilarious
anecdote of appearing before an panel of professors who are assessing his
PhD dissertation.

All is going well when one of the professors asks, "Cliff, why is the sky blue?"

I just Googled and by luck there is this fabulous 2 minute 46 second
YouTube video from some years back when Stoll was interviewed by
the U.S. NBC network where he provides that account of the PhD interview.

I suspect like the question that Stoll is forced to try and answer in ever
increasing detail, the true answer to your question might well prove to
be as equally layered and complex :)

If you want a good laugh, I recommend this short video :lol: :-

https://youtu.be/yfm3MFj6LLU


As a postscript I was lucky enough to meet a couple of visitors from the
US last year, one of whom was a retired professor of astronomy.
During conversation I mentioned the Stoll "why is the sky blue" story
and as it turned out they not only knew the story, they were also
friends of Clifford Stoll.

Which might beg the question, "Why is the world so small at times?" :lol:

Wavytone
06-03-2019, 03:31 PM
Google "Pousse Cafe"

Jeff
06-03-2019, 09:14 PM
Great question Markus!

I've done a few searches myself. Seems to be a combination effect of powerful convection currents, and varying gas types/densities.
I found the following article particularly interesting:

https://www.forbes.com/sites/jesseshanahan/2018/08/16/what-causes-jupiters-iconic-striped-appearance/#6f90ab917ed0

Stonius
06-03-2019, 10:01 PM
Interesting article. Of course, only Jupiter would have a giant polar cyclone surrounded by 8 smaller cyclones. 😀

Sunfish
20-03-2019, 10:44 AM
So the apparent clouds and storms on Jupiter are more like aurora than vapour clouds on earth. .?

Cohesive magnetic lines.

Every planet and moon seems to have its surprising extremes. Ice oceans. Boiling gases. A universe of different worlds.

Interesting links.