Adiabatic lapse rate

On Oct 21, 2:29 pm, Mitty wrote:
On 10/21/2007 11:44 AM, Everett M. Greene wrote the following: Does the lapse rate equation hold in all cases?

Don't count on it in the real world. I was once in the clear at 6,000 feet, 0
degrees C, and confidently told my wife that Approach would soon drop us into
the clouds at 4,000 feet but that we didn't have to worry about ice because it
would be +4 degrees. When we got there it was -- ta da -- 0 degrees! We
immediately started picking up some light ice, requested and got a descent to
3,000, and all was well.

In fact I've noticed when there is ice about and the temp is near
freezing that
it tends to stay that way -- no rate at all!!

It's as if the model is more like the ice-water mix where the temp is
constrained
at 32F until all the ice is melted or all the water frozen.

Look out, huh! It's an interesting question on the instrument written
but the real world is a lot different.

Bill Hale

Bill wrote:

In fact I've noticed when there is ice about and the temp is near
freezing that
it tends to stay that way -- no rate at all!!

I've noticed that too, and always assumed its because of the ice
buildup on the thermometer.

Latent heat. That is why they spray water on the oranges to
reduce frost damage.

After a day or two at below freezing, but near freezing
temperatures in stable air, there will be little airframe
ice because the water has finally frozen.
But with unstable air, more fresh and liquid water is being
cooled into the supercooled range and that makes structural
ice.


wrote in message
ups.com...
|
| Bill wrote:
|
| In fact I've noticed when there is ice about and the
temp is near
| freezing that
| it tends to stay that way -- no rate at all!!
|
| I've noticed that too, and always assumed its because of
the ice
| buildup on the thermometer.
|