Sounds like a problem for spring 2005. Any reason for the lower than
usual temps. The "Ozone hole" was alway over the ant arctic because of
the lower temps found there compared to the actic.

=============
Record low temperatures over the North Pole are thinning the
protective ozone layer, a condition which could affect human health in
northern countries and even central European nations, the European
Union warned Monday.

"Large ozone losses are expected to occur if the cold conditions
persist," said European Commissioner for Science and Research Janez
Potocnik.

He said the first signs of ozone loss have been observed after an
extremely harsh winter above the Arctic.

The ozone layer keeps out ultraviolet radiation, which is dangerous to
humans and animals. Less protection could increase risks of skin
cancer and affect biodiversity, scientists say.

Because of the record lows over the Arctic, scientists have been put
on alert to monitor closely the condition of the ozone layer over the
coming months.

"The meteorological conditions we are now witnessing resemble and even
surpass the conditions of the 1999-2000 winter -- when the worst ozone
loss to date was observed," said Dr. Neil Harris of the European Ozone
Research Coordinating Unit in Britain.

He said temperatures at a 20 kilometer (12 mile) height had dropped to
an average of minus 80 degrees Celsius (minus 112 degrees Fahrenheit),
the lowest over the Arctic in half a century.

People in some northern countries who work out in the open should
taken special precautions for sun protection in a month, Harris said.

While there are considerable year-to-year variations in the Arctic,
there has been ozone loss in the southern Antarctic during almost all
winters since the late 1980s.

"The concern is that the Arctic appears to be moving into
Antarctic-like conditions which will result in an increase in UV
radiation levels that will have consequences on human health in
northern hemisphere countries," the statement of the EU head office
said.

It said the hole in the ozone layer could affect areas around the
polar zone, Scandinavia and even down to central Europe.
===========

"Simon S" wrote
snip
European Commissioner for Science and Research Janez Potocnik.
.....said
temperatures at a 20 kilometer (12 mile) height had dropped to
an average of minus 80 degrees Celsius the lowest over the Arctic in half
a century.

Question. Might this paradoxically be a sign of global warming?

My thinking is along the lines that the temperature in the stratosphere is
often LESS over tropical regions than it is in polar regions. This is
largely because the tropopause (the start of the stratosphere) in at a much
lower height over polar regions than it is at the equator.

What is really needed in order to make sense of that announcement is how the
height of the tropopause in the Artic compares now with what it has been
previously.

Jack
-

I have already posted this, but no one sadly seemed interested.:-(

D.

Jack Harrison wrote:

"Simon S" wrote
snip

European Commissioner for Science and Research Janez Potocnik.

....said

temperatures at a 20 kilometer (12 mile) height had dropped to
an average of minus 80 degrees Celsius the lowest over the Arctic in half
a century.

Question. Might this paradoxically be a sign of global warming?

It could be a marker but only time will tell. The stratosphere may get
slightly cooler as the troposphere warms. It is complicated by the ozone
layer thinning. There have been a couple of papers about it fairly recently.

Perhaps more of interest to the UK weather watchers it might just
presage the appearance of nacreous clouds visible from the UK if we are
lucky. The ozone level over Uccle is dropping pretty rapidly so it is a
possibility. Please report any sightings (photos too if possible).

Regards,
Martin Brown

In article , Martin Brown writes:
Jack Harrison wrote:

"Simon S" wrote

temperatures at a 20 kilometer (12 mile) height had dropped to
an average of minus 80 degrees Celsius the lowest over the Arctic in half
a century.

Question. Might this paradoxically be a sign of global warming?

It could be a marker but only time will tell. The stratosphere may get
slightly cooler as the troposphere warms. It is complicated by the ozone
layer thinning. There have been a couple of papers about it fairly recently.


The stratosphere has been cooling and contracting for 40 years. This is
what is expected as the troposphere warms up. We have direct measurements
of the height of the ionosphere (from Stanley, Falkland Isles) for the
past 40 years showing a steady lowering of 35 Km over that period.

Of course, the cooling also facilitates the destruction of ozone, which is
why ozone depletion has not decreased in line with the drop in production of
CFCs etc.

Jack is spot on.


Cheers,

keith




---
Iraq: 6.5 thousand million pounds, 80 UK lives, and counting...
100,000+ civilian casualties, largely of coalition bombing...

"Jack Harrison" wrote in message
.. .

"Simon S" wrote
snip
European Commissioner for Science and Research Janez Potocnik.
....said
temperatures at a 20 kilometer (12 mile) height had dropped to
an average of minus 80 degrees Celsius the lowest over the Arctic in half
a century.

Question. Might this paradoxically be a sign of global warming?

My thinking is along the lines that the temperature in the stratosphere is
often LESS over tropical regions than it is in polar regions. This is
largely because the tropopause (the start of the stratosphere) in at a much
lower height over polar regions than it is at the equator.

What is really needed in order to make sense of that announcement is how the
height of the tropopause in the Artic compares now with what it has been
previously.

There was a paper in Science recently about changes in the height of the
tropopause. Here is a description of it.
http://www.llnl.gov/str/March04/Santer.html

I have not read it myself yet, so I do not know if it refers to the Arctic.

Cheers, Alastair.

"Jack Harrison" wrote in message
.. .

"Simon S" wrote
snip
European Commissioner for Science and Research Janez Potocnik.
....said
temperatures at a 20 kilometer (12 mile) height had dropped to
an average of minus 80 degrees Celsius the lowest over the Arctic in half
a century.

Question. Might this paradoxically be a sign of global warming?

Hi Jack,

I have just found this report which backs up your idea.

Evidence suggests that global warming enhances destruction of ozone layer
By DENNIS BUECKERT
OTTAWA (CP) - Two major environmental problems once thought to be unrelated -
climate change and ozone depletion - appear to be closely linked in ways that
will delay recovery of the ozone layer, scientists say.

Growing evidence suggests that global warming favours destruction of ozone in
the stratosphere, jeopardizing the achievements of the 1987 Montreal Protocol
to protect the ozone layer. One signal of the ozone-climate link is the sharp
ozone depletion over the Arctic this winter, says Environment Canada scientist
Tom McElroy in an interview Thursday.

See below for the full article
http://cnews.canoe.ca/CNEWS/Science/...919503-cp.html

Cheers, Alastair,

In article , "Alastair McDonald" k writes:

"Jack Harrison" wrote in message
. ..

"Simon S" wrote
snip
European Commissioner for Science and Research Janez Potocnik.
....said
temperatures at a 20 kilometer (12 mile) height had dropped to
an average of minus 80 degrees Celsius the lowest over the Arctic in half
a century.

Question. Might this paradoxically be a sign of global warming?

Hi Jack,

I have just found this report which backs up your idea.

Evidence suggests that global warming enhances destruction of ozone layer
By DENNIS BUECKERT
OTTAWA (CP) - Two major environmental problems once thought to be unrelated -
climate change and ozone depletion - appear to be closely linked in ways that
will delay recovery of the ozone layer, scientists say...


See below for the full article
http://cnews.canoe.ca/CNEWS/Science/...919503-cp.html



Good grief. Have they been asleep all these years? BAS published all
of this way back in 1998 in the Journal of Geophysical Research...

....and as mentioned in an aside in uk.sci.weather in October 1998:

http://makeashorterlink.com/?C6D93666A



So folks... you heard it here first, and way before those sleepy
Canadians.



Cheers,


keith



---
Iraq: 6.5 thousand million pounds, 80 UK lives, and counting...
100,000+ civilian casualties, largely of coalition bombing...