On 07/12/2010 20:02, Col wrote:
"Lawrence wrote in message
eb.com...
Some amazing charts tonight there's one synoptic set up showing as Steve
Murr said on TWO -a cross polar flow. Now that really does look
grotesquely special
http://www.meteociel.fr/modeles/ecmw...1-216.GIF?07-0

It's like the NH climate is taking drugs !!!!!! Quite unerving to see
such set ups
I've never really looked at polar orientated charts like this so
I don't know how unusual this set-up is. What I always thought
of the North Pole in winter was a weak area of high pressure
(or at least a col) with low pressure systmems circulating around it.

What difference would it make if our arctic northerly happened to
start off life as a southerly from the Atleutian Islands?

It's all just polar air and the wind at the North Pole is *always*
a southerly
The situation at our end of the globe is a bit more interesting than the
Antarctic. The South Pole is in the middle of a large and very cold
continent covered with ice. This produces a strong polar vortex - at
least in the middle to upper atmosphere - and the Antarctic cold is also
"protected" to a large extent by ocean currents.

In the Arctic, the North Pole and surrounding regions are not the
coldest areas. It gets much colder in Siberia and considerably colder
in the Canadian Arctic. There is also the Greenland ice-cap which is
some distance from the North Pole.

So you would expect to see a more complex flow in the Arctic basin
because the temperature pattern is not as straightforward as it is near
the South Pole.

Warming of the Arctic Ocean and reduction of the sea ice extent would
further complicate the situation. I recall someone (was it Will?)
remarking on here that climate warming in the Arctic might produce more
of these cold winter episodes round our part of the world by disrupting
the flow pattern and so weaken the expected westerly winds.

--
- Yokel -

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