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Stratosphere (Was Single Line Report)



Jon Wagner (wjon@okcforum.osrhe.edu) wrote:
: I seem to remember an article about studying winds aloft where a couple of 
: parafoils were used to keep instrumentation up in the air for a week or two at
: least.  of course, if I remember correctly, it was down in the eastern trade
: winds between 33 degrees north and the equator.

A couple of months ago (?) Charlie Hubbard also wrote about flying his
deltas up a ways.....and, as I recall, there was a bit of discussion
about how high kites have flown, and where was the stratosphere anyway?
At least I couldn't remember, didn't look it up, but I read this bit
this weekend and thought it might be interesting to others.

>From the book "Understanding the Sky -- A  Sport Pilot's Guide to
Flying Conditions"

The Big Picture

The atmosphere is held to the earth by gravity.  Although the total thickness 
of the atmoshphere exceeds 500 miles (800 km), most of the air is packed 
near the earth's surface since air is compressible and gravity pulls each 
molecule downward.  In fact, fully half of the atmosphere's total weight of 
over 5.6 quadrillion (5,600,000,000,000,000) tons is below 18,000 feet
(5,500 m)!

The atmosphere can be divided into different levels like the layers of an 
onion according to certain characteristics.  We are mainly interested in the 
lowest layer which is known as the troposphere (tropo means change).  It is 
here where the changes take place that we identify as weather.  It is here 
that we live and breath and fly.

The troposphere extends from the surface to 5 or 6 miles (7 to 9 km) at the 
poles and 10 to 12 miles (17 to 20 km) at the equator.  The reason for this 
difference is centrifugal effects due to the earth's spin [stuff about 
illustration not included].  To put matters in perspective, the entire 
atmosphere compared to the earth would only be about the same relative 
thickness as the peel of an orange while the troposphere's thickness would 
be equivalent to the skin of an apple.

On top of the troposphere lies the stratosphere and the transition between 
the two is known as the tropopause.  The way we differentiate these two 
lower layers is that the temperature drops steadily with height in the 
troposphere but it remains nearly constant as we climb into the 
stratosphere.  Thus the stratosphere is stable and clear but the troposphere 
exhibits clouds and a wide variety of conditions.  The troposphere is our 
sphere of interest in this book.


The author is Dennis Pagen, and the book is published by him at this
address:  P.O. Box 101, Mingoville, PA 16856 USA
US$20 at the local hang gliding/paragliding ( = parapente) store.
 
ISBN 0-936310-03

My husband Steve is a beginning paraglider and reading it.  He says he
thinks I'll find it interesting (this is a household that is generally
interested in weather), but not specifically helpful for kiteflying,
except for the chapter on local conditions which might help me determine
where and what kind of winds are in a strange location (say you're driving
somewhere and looking out over a broad area and wondering where the best
place to fly might be). While most of the examples use U.S. locales, the
author gives information on differences between northern and sourthern
hemisphere conditions, and also comments on specific phenomena in Europe
and other places hang glider/paragliders congregate.

This bit on the stratosphere is on pages 1 and 2, so you can see I'm
speeding through it!

Anne


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 *  Berkeley, California       |       Give without remembering            * 
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