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Re: Hurricane



Hi,

The primary storage of energy in weather systems is in the latent heat
of evaporazation. When water vapor in the air condenses, a large amount of
energy is available to heat the surrounding air ( which in the clouds is well
below 0 C ) This warmer ( relative to the surrounding air ) air mass rises,
and other air moves in to take its place. On the scale of large weather
systems rotation is caused by coriolis forces of this air moving to replace the
warm rising air.

An additional note: In many ( most that produce rain) clouds the
transition is not from vapor to liquid but vapor to solid. This is due to the
different vapor pressures of liquid and solid water, but this does not change
the above argument.

Thanks
Roger Haar

********************************
kyle forinash wrote:

Ok, well I did ask for a simple explanation but now I'd like to know more.
How the heck does a huricane change random thermal motion into 150mph
winds? This is a neat trick (and at first glance would appear to contradict
the second law of thermo...).

kyle

At 9:27 AM -0400 9/30/98, Herbert H Gottlieb wrote:
On Wed, 30 Sep 1998 07:39:29 -0400 kyle forinash <forinas@indiana.edu>
writes:
As long we are on the subject of hurricanes- can anyone give a short
explanation of how hurricanes come to be, in particular, why do they
gain energy while over water (but lose energy over land)?

Over water, the warm winds pick up the fast moving (energetic) water
molecules
that have escaped from the surface by evaporation.

Over land, the winds are slowed by friction with the surface.

Herb Gottlieb from New York City
(Where we never have hurricanes but everyone is always in a hurry)

-----------------------------------------------------
kyle forinash 812-941-2390
forinas@indiana.edu
Natural Science Division
Indiana University Southeast
New Albany, IN 47150
http://Physics.ius.indiana.edu/
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