Clouds

[REASON]

That one's amazing Doug! What an awsome photo.

That one would make an excellent framed poster.

[freeztar]

Awesome photo Doug!

It's funny because I was looking for this thread a few days ago. I didn't think to look in the physics forum.

Anyhow, here are some more great cloud shots:
Clouds Pictures, Clouds Wallpapers, Download, Photos -- National Geographic

[HydrogenBond]

If you look at clouds, in general, what we have is a phase separation from the atmosphere, where high entropy water vapor, originally fully dissolved in the air, lowers entropy. We don't get this affect with the O2 and N2, with either of these forming higher concentration pockets. The difference is because of the hydrogen bonding that can occur in water. The water can lower entropy because of the net energy that can be released because of this moderately strong EM attraction. Clouds will still contain entropy, but it is less than the surrounding O2 and N2, which are EM neutral.

If we were to take a sample of a cloud, i.e., cubic meter, the amount of water in that sample is higher than what one would expect from water saturation in the air, where the water is fully dissolved in the air. It is because it is existing as a separate phase with the EM attraction allowing more water to collect in one area. If we condense this water we essentially remove its higher percentage impact on the vapor space. The result is a loss of partial pressure, pulling a slight vacuum, i.e., low pressure.

A loose experiment is a jar of air with a rod in the jar. We have a rubber collar in the lid, where the rod goes through. It is an air tight seal. If we pull the rod out of the jar, with the collar seal not allowing air to leak in, the result is the same air has to occupy more space to make up for the volume the rod once occupied. The result is a vacuum. In the case of rain, the rod-gasket is going from vapor to liquid-solid causing about a 1000 fold reduction in the original space the water had been occupying. This is also driven by the EM forces in the water, with liquid water the more stable state.

[Turtle]

Not all clouds are created equal. Here's a beautimous (if not oversized.)shot of some noctilucent clouds from the space station:
http://spaceflight.nasa.gov/gallery/...017e011632.jpg

[Turtle]

I shot these clouds yesterday. 48 minutes elapsed time, compressed to 5.

YouTube - Cloud Stream

[Turtle]

In this time lapse video, 98% of the clouds start as jet contrails. Elapsed time is 2 hrs 20 mins, starting about 4:40pm Pacific time. Looking South from Vancouver USA.

YouTube - Contrails over the Columbia

[Turtle]

Just caught these suggestive formations out my South window as they move East over P-Town.

Altocumulus undulatus

Originally Posted by Wiki

...As with other altocumuli, the undulatus variety can form in all seasons, announcing an approaching system within the general area (about 100 - 200 mi or 160 - 322 km). They result from wind shear (an abrupt speed or directional shifting in the wind, acutely changing with height). Lines one might see indicate the direction of the shear. ...

[Moontanman]

Originally Posted by Turtle

Just caught these suggestive formations out my South window as they move East over P-Town.

Altocumulus undulatus

A mackerel sky, cool.....

[Moontanman]

Originally Posted by HydrogenBond

If you look at clouds, in general, what we have is a phase separation from the atmosphere, where high entropy water vapor, originally fully dissolved in the air, lowers entropy. We don't get this affect with the O2 and N2, with either of these forming higher concentration pockets. The difference is because of the hydrogen bonding that can occur in water. The water can lower entropy because of the net energy that can be released because of this moderately strong EM attraction. Clouds will still contain entropy, but it is less than the surrounding O2 and N2, which are EM neutral.

If we were to take a sample of a cloud, i.e., cubic meter, the amount of water in that sample is higher than what one would expect from water saturation in the air, where the water is fully dissolved in the air. It is because it is existing as a separate phase with the EM attraction allowing more water to collect in one area. If we condense this water we essentially remove its higher percentage impact on the vapor space. The result is a loss of partial pressure, pulling a slight vacuum, i.e., low pressure.

A loose experiment is a jar of air with a rod in the jar. We have a rubber collar in the lid, where the rod goes through. It is an air tight seal. If we pull the rod out of the jar, with the collar seal not allowing air to leak in, the result is the same air has to occupy more space to make up for the volume the rod once occupied. The result is a vacuum. In the case of rain, the rod-gasket is going from vapor to liquid-solid causing about a 1000 fold reduction in the original space the water had been occupying. This is also driven by the EM forces in the water, with liquid water the more stable state.

HB, it's temperature not hydrogen bonding, if it was cold enough O2 and N2 would both form clouds and precipitation and snow.

[Turtle]

Originally Posted by Moontanman

A mackerel sky, cool.....

Thank you for that term. I had to look it up, and found that it may apply to a variety of forms, besides the Altocumulus undulatus. Anyway, I got a shot today of another form of mackeral sky. This is looking WSW.



Altocumulus mackerel sky - Wikipedia, the free encyclopedia

Originally Posted by Wiki

A mackerel sky is an indicator of moisture (the cloud) and instability (the cumulus form) at intermediate levels (2400-6100 m, 8000-20,000 ft). If the lower atmosphere is stable and no moist air moves in, the weather will most likely remain dry. However, moisture at lower levels combined with surface temperature instability can lead to rainshowers or thunderstorms should the rising moist air reach this layer. In the winter it is often said to precede snowstorms and flurries. Mackerel skies are spoken of in the popular bywords, "Mackerel in the sky, three days dry," and "Mackerel sky, mackerel sky. Never long wet and never long dry." The phrase 'mackerel sky' came from the fact that it looks similar to the markings of an adult king mackerel.