# Viscous Shear vs Hydrostatic: Can Warmer Water "Float" Above Average Mean Level?

Fluids cannot withstand shear forces or "water seeks it's own level" in the less than quantitative common expression.
In real life fluids exert and receive shear forces. Viscosity is in fact a measure of shear force /unit area. Water just isn't going to flow fast on a gradient of, say, 0.00000002, the 2.5" sea level drop from Norfolk to NY.
To keep things simple and easy first set up this problem without taking into account curvature of the earth. Viscosity is const. and only the density varies with temp.
The initial condition is the warmer "packet" of water is a single uniform warmer temperature and cylindrical extending from the floor to the surface inside of a larger radius cylindrical reservoir. There are no independent currents or other issues.
How fast will the center of the warm water rise?
Bret Cahill
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On Wed, 4 Jul 2012 09:43:37 -0700 (PDT), Bret Cahill wrote:

Your problem is not defined completely.
What temperatures are the waters?
If the warm column stays intact, it will be decelerating due to weight that is above the surface of the cold water.
Bouyance force varies with the square of the radius.
Shear force varies with the radius.
You didn't draw a picture of your problem before posting, did you?
What do you think this problem will illustrate?
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Everything you need to set up the general problem has been stated.

If you had any math back ground you'd know that you could enter those numbers later.

"If"
That's what the _goal_ of the problem.
You can use 'puter modeling if you want.
Bret Cahill
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On Wed, 4 Jul 2012 16:38:37 -0700 (PDT), Bret Cahill wrote:

Nice deflection.
Where is the clue that you were asking for a formula and not a number?

After the portion of the column sticking out of the water balances the bouyancy due to the difference in density and the viscosity damps out the oscillation, the speed will be zero.

No 'puter model needed.
Why do Warmists want to point to computer models when they are neither necessary nor helpful?
Computer models are not a substitute for thinking.
Basing the question on a free body diagram of the situation you wanted to ask about might have helped.

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From the fact that you don't know how to use variables?

From the fact that no numbers were specified.
Duh . . .

Why not just admit that climate change can cause changes to regional differences in sea level?

What oscillation?

You've dug yourself into a hole. The first thing you need to do is stop digging.
Bret Cahill
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On Wed, 4 Jul 2012 20:12:52 -0700 (PDT), Bret Cahill wrote:

Release a submerged, stationary object that is lighter than the surrounding water, and it will gain upward momentum. The bouyancy force is decreasing all the time the object is rising above the surface, but it isn't zero until the weights are equal. But the object still has upward momentum, so it will overshoot.
It will bob up and down until viscous friction makes it stop.
Then:

Also, it is usually a good idea to draw a free body diagram when contemplating a problem. Especially before posting to request an answer to the problem.

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A solid float doesn't dissipate mechanical energy internally.
Maybe a [former] Raleigh Taylor instability might slosh back and forth but here the water would "bob" up once in the center and then flow out and down over the top of the cold.

Fluid mechanics will always be a bear of a problem. That's why they invented super computers. A hundred years from now they'll _still_ be coming up with improvements in Olympic swimming tactics.
This was just to get deniers to understand that sea level is more complicated than water at a uniform temperature in a bath tub.
Bret Cahill
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Actually I was thinking of a Raleigh-Bernard

and that doesn't really oscillate either.

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Possibly Wally W. posted Wed, 04 Jul 2012 21:35:09 -0400

If he wanted output number, he would put in input number.
--
Poutnik

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Dear Bret Cahill:
On Wednesday, July 4, 2012 9:43:37 AM UTC-7, Bret Cahill wrote: ...

Quite fast, actually.
This is old news in hot water heaters. The tank temperature stratifies (at least in an electric water heater). The stuff at the top is hottest, and he stuff near the bottom is relatively cool.
David A. Smith
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This is part of the ongoing effort to get deniers interested in fluid mechanics, admittedly a tricky complicated field and less interested in simple minded conspiracy theories.

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how different is the heighth of the geoid, due to differnce of lattitude?... I assume that the geoid is the normal 'zero" for mean sealevel; is that, so?

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anyone got a handle on the comparitive absorptive spectra of dihydrogen oxide and dioxygen carbide?... if so, please, fill in the blanks on the Exploratorium/Westinghouse chart of all known radiation, sources & uses; thank you!
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You can get help.
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I know, I can consult the googolplex, but that isn't what I do.
surf's on!
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