"yttiw" wrote in message
news:2013050910130752063-cuddles@britpostcom...

I think that you may be confusing many separate subjects here.

The usual usage of the word thickness is for the height difference between
two atmospheric levels, such as the 1000mb and 500mb.

Cold air will be denser than warm, and therefore the difference in height
between the two pressure levels will be less. It is much easier to attach
a pressure sensor to a balloon which can be filled with a precise amount
of gas so that it rises through the atmosphere at a steady rate. By this
method the time taken to reach various pressure levels, 850mb, 700mb, etc.
can be read from a stopwatch, and the heights of those levels calculated.
Subtract one height from another, and you have the 'thickness'.

Well, you could use that method, but the result would be subject to
considerable error. It is possible to cause a balloon to ascend at an
approximately fixed rate, though already with a certain margin or error. But
it has to be recognised that the 'fixed rate' of ascent is through an
assumed benign medium which is neither ascending or descending itself. This
is almost never the case in the atmosphere, where waves and eddies are
embedded on a multitude of scales. Thus the possibility of obtaining
anything other than an approximate thickness is vanishingly small.



--
Bernard Burton

Wokingham Berkshire.

Weather data and satellite images at:
http://www.woksat.info/wwp.html