Two articles in the Guardian today, one stating that global warming is slowing the jet stream, and the other stating that it is increasing and will cause a higher incidence of in flight turbulence.

"Climate change will lead to bumpier flights", say scientists
Paul Williams, at the University of Reading who led the new research.

"The jet streams, which meander for thousands of miles, are driven by the temperature difference between the poles and the tropics, Williams explained.. Climate change is heating the Arctic faster than lower latitudes, because of the rapid loss of reflective sea ice, so the temperature difference is growing."




"Why our turbulent weather is getting even harder to predict"
*Nicholas Klingaman of Reading University

"......However, in recent years this giant river of air has begun to meander and to slow down.....*

"The trouble is that the gradient between the atmosphere in the lower latitudes and in the Arctic is being disrupted by global warming," said Francis.
"As the Arctic heats up disproportionately, so does the atmosphere at the north pole and as it warms up, it rises. The net effect has been to erode the gradient between the top of the atmosphere over the tropics and the top of the atmosphere over the Arctic. Less air pours down towards the north pole and less air is whipped up by Earth's rotation to form the jet stream. It is becoming less of a stream and is behaving more like a sluggish estuary that is meandering across the upper atmosphere at middle latitudes."

Maybe these guys need to get together and decide who is right!

Mike McMillan

IOW

On Tue, 9 Apr 2013 06:19:15 -0700 (PDT)
Mike McMillan wrote:

"The jet streams, which meander for thousands of miles, are driven by
the temperature difference between the poles and the tropics,
Williams explained. Climate change is heating the Arctic faster than
lower latitudes, because of the rapid loss of reflective sea ice, so
the temperature difference is growing."

All was going so well until the last word! What will he do for his next
trick, prove that black is white?

--
Graham P Davis, Bracknell, Berks.
Free office softwa http://www.libreoffice.org/
Carlos Seixas, Sonata nº 1 - best version of this I've found:
http://www.youtube.com/watch?v=YXox7vonfEg

In article ,
Mike McMillan writes:
"Climate change will lead to bumpier flights", say scientists Paul
Williams, at the University of Reading who led the new research.

"The jet streams, which meander for thousands of miles, are
driven by the temperature difference between the poles and the
tropics, Williams explained. Climate change is heating the Arctic
faster than lower latitudes, because of the rapid loss of reflective
sea ice, so the temperature difference is growing."

That makes no sense. The temperature difference is growing less.
--
John Hall
"Madam, you have between your legs an instrument capable
of giving pleasure to thousands and all you can do is scratch it."
Sir Thomas Beecham (1879-1961) to a lady cellist