Super Cooled Water

[slick1537]

I understand why it is a danger to A/C. I also understand that it can be found in clouds. However I have a hard time understanding how or why it forms. Anyone care to explain how water can stay liquid below its freezing? My best guess is that water molecules form on nuclei in the cloud, then may split. Some water is left without a nuclei, and continues to cool until it comes in contact with something with which to freeze onto, whether it be another nuclei or an a/c wing.

 

- Slick

[PhotoFlyer]

The simple answer is that water needs some kind of "seed" for ice crystals to grow on. The seed could be another ice crystal, dirt, polution, or any other small particle.

 

Check out this wiki for a little more information.

[AngelFire_91]

You are exactly right, the water drop needs something to attatch to (nuclei), to freeze. If there isn't such things in the cloud, then it will stay supercooled. It will eventually freeze, it's just a lot colder then freezing before it does. This is the whole basis behind weather modification. I used to fly weather research and modification, and let me tell you. We did a research flight a while ago on supercooled clouds. There is a hugh difference between supercooled clouds and normal clouds when it comes to ice accumulation.

Edited November 26, 2007 by AngelFire_91

[Superman]

You are exactly right, the water drop needs something to attach to (nuclei), to freeze.

 

And if that "something" happens to be what your flying, you better get it the hell out of there quick.

 

I don't know that you need to be in the clouds to get into it. If you are flying under an inversion layer in cold temps and rain, it can freeze on impact. But I don't know that that qualifies as "supercooled." AngelFire would probably be the authority on that.

 

Either way, freezing rain and aircraft don't mix well

 

 

Fly Safe

Clark

[Gomer Pylot]

Oh, they mix only too well, and become firmly united. That's the problem.

[kodoz]

I don't know that you need to be in the clouds to get into it. If you are flying under an inversion layer in cold temps and rain, it can freeze on impact. But I don't know that that qualifies as "supercooled." A

 

Freezing rain is supercooled, so no, you don't need to be in the clouds to encounter supercooled water.

[Sparker]

Aren't some rivers in the mountains way below freezing, except they are still flowing because the water can't slow down enough to freeze?

 

Or......

 

I'm dumb.

[AngelFire_91]

If you are flying under an inversion layer in cold temps and rain, it can freeze on impact. But I don't know that that qualifies as "supercooled."

 

In most cases that is true, it would be supercooled. There are also times that the lower layer of temps could be shallow enough that it's below freezing but not supercooling. So you have rain that's freezing, but not rain freezing on impact, if that makes sense. A lot of people will still call it freezing rain, which it is, it's just not freezing as fast. So basically it can be or doesn't have to be supercooled to be freezing rain. It's all in how you perceve it. I'll say the true defenition of freezing rain is supercooled though.

Edited November 27, 2007 by AngelFire_91