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-   -   The answer is jet stream, now what's the question? (https://www.weather-banter.co.uk/uk-sci-weather-uk-weather/181558-answer-jet-stream-now-whats-question.html)

xmetman August 11th 15 10:35 AM

The answer is jet stream, now what's the question?
 
After listening to Carole Kirkwood talking about what a wet and cold summer its been over Scotland this year on this mornings Breakfast Weather, it does seem to me that as far as the media are concerned most of today's weather woes in this country today, including this one can be blamed on the jet stream, or lack of jet stream, or the position of the jet stream. So if the answer to most of the world's climate problems is the ubiquitous "jet stream", what about its part in global warming? I haven't seen any research that looks into the role jet streams play in global warming, but I'm sure it won't be long before there is a slew of scientific papers about it.

If this is true, just what controls the position and strength of the jet stream, and the answer to that must be the general atmospheric circulation, but of course that's not half as catchy, dynamic or sexy as the phrase "jet stream". I just can't imagine John Hammond for instance spending an hour in a BBC Horizon program to explain the intricacies of the Hadley cell and the northeast trade winds, when he can talk over a 3D animation and fly through of a North Atlantic super jet blowing at 250 knots.

I'm sure that the phrase "jet stream" will be cropping in many conversations about the weather in the coming years, you can easily picture one old dear saying to another in a bus queue "I know Enid the weather has been simply terrible, and you know it's all down to the orientation of the Jet stream over Iceland you know".

https://xmetman.wordpress.com/
http://xmetman.com/

Graham P Davis August 11th 15 11:45 AM

The answer is jet stream, now what's the question?
 
On Tue, 11 Aug 2015 02:35:01 -0700 (PDT)
xmetman wrote:

After listening to Carole Kirkwood talking about what a wet and cold
summer its been over Scotland this year on this mornings Breakfast
Weather, it does seem to me that as far as the media are concerned
most of today's weather woes in this country today, including this
one can be blamed on the jet stream, or lack of jet stream, or the
position of the jet stream. So if the answer to most of the world's
climate problems is the ubiquitous "jet stream", what about its part
in global warming? I haven't seen any research that looks into the
role jet streams play in global warming, but I'm sure it won't be
long before there is a slew of scientific papers about it.


There have been several suggestions that the differential warming of
the Arctic and the Tropics will weaken the Jet Stream due to a
reduction in thermal contrast. This weakening of the Jet would then
lead to large meanders in the Stream and long spells of severe
weather, either cold or hot. This idea seems to have been accepted
though it bothered me a bit when I actually started to think about it.

I recall being taught (which I accept does not necessarily mean I was
taught) that slow-moving or stationary upper waves are associated with
a strong Jet; small, transitory waves are associated with weak Jet
Streams.

Then I found an article by CEP Brooks in an online 1950 issue of
Weather which said more or less the same thing. It also said that
they'd expected a weakening of upper winds due to the differential
warming that had occurred before WWII and had been surprised to find
that they'd strengthened instead.


If this is true, just what controls the position and strength of the
jet stream, and the answer to that must be the general atmospheric
circulation, but of course that's not half as catchy, dynamic or sexy
as the phrase "jet stream".


One thing that has an effect on the atmospheric circulation, as I've
said before, is the pattern of SST anomalies, particularly in the Grand
Banks region.


--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/




Alastair McDonald[_2_] August 11th 15 12:32 PM

The answer is jet stream, now what's the question?
 
"xmetman" wrote in message
...

I'm sure that the phrase "jet stream" will be cropping in many conversations
about the weather in the coming years, you can easily picture one old dear
saying to another in a bus queue "I know Enid the weather has been simply
terrible, and you know it's all down to the orientation of the Jet stream
over Iceland you know".

=========================

Didn't we get a bad summer a few years ago when even people in the bus queue
were blaming the Jet Stream?

I monitored the jet stream for a few months and the weather here did seem to
be bad - wet and windy - when the jet stream was passing over the UK. It is
also hot here in summer when the Jet Stream is to the north of us.

The current Jet Stream is shown he
http://virga.sfsu.edu/gif/jetstream_atl_init_00.gif
And it position 6 days ahead he
http://virga.sfsu.edu/gif/jetstream_atl_h120_00.gif

Does that mean it is going to be cold nex Sunday?

Cheers, Alastair.




Martin Brown August 11th 15 12:43 PM

The answer is jet stream, now what's the question?
 
On 11/08/2015 10:35, xmetman wrote:
After listening to Carole Kirkwood talking about what a wet and cold summer its been over Scotland
this year on this mornings Breakfast Weather, it does seem to me that

as far as the media are concerned
most of today's weather woes in this country today, including this

one can be blamed on the jet stream,
or lack of jet stream, or the position of the jet stream.


They tend to over simplify. Jet stream location and strength is mostly
of interest to commercial airline operators and optical astronomers.

So if the answer to most of the world's climate problems is the ubiquitous "jet stream", what about its
part in global warming? I haven't seen any research that looks into

the role jet streams play in global warming,
but I'm sure it won't be long before there is a slew of scientific

papers about it.

You could always try feeding suitable terms into a search engine. eg.

http://www.scientificamerican.com/ar...ore-pollution/

Or for the wet summer of 2012 also blamed in part on the jet stream:

http://blog.metoffice.gov.uk/2012/07...limate-change/

If this is true, just what controls the position and strength of the jet stream, and the answer
to that must be the general atmospheric circulation, but of course

that's not half as catchy,
dynamic or sexy as the phrase "jet stream". I just can't imagine John

Hammond for instance spending
an hour in a BBC Horizon program to explain the intricacies of the

Hadley cell and the northeast trade winds,
when he can talk over a 3D animation and fly through of a North

Atlantic super jet blowing at 250 knots.

I think they *have* done stuff on the trade winds and roaring forties a
lot more often than you give them credit for.

I'm sure that the phrase "jet stream" will be cropping in many conversations about the weather in the coming years,
you can easily picture one old dear saying to another in a bus queue

"I know Enid the weather has been simply terrible,
and you know it's all down to the orientation of the Jet stream over

Iceland you know".

It might even be true.

It seems that when the jet stream takes to meandering around it can trap
weather in a nearly static configuration over the UK.

--
Regards,
Martin Brown

Dawlish August 11th 15 12:45 PM

The answer is jet stream, now what's the question?
 
On Tuesday, August 11, 2015 at 12:37:59 PM UTC+1, Alastair wrote:
"xmetman" wrote in message
...

I'm sure that the phrase "jet stream" will be cropping in many conversations
about the weather in the coming years, you can easily picture one old dear
saying to another in a bus queue "I know Enid the weather has been simply
terrible, and you know it's all down to the orientation of the Jet stream
over Iceland you know".

=========================



I monitored the jet stream for a few months........


Idiot.


Graham Easterling[_3_] August 11th 15 01:10 PM

The answer is jet stream, now what's the question?
 
On Tuesday, August 11, 2015 at 11:46:00 AM UTC+1, Graham P Davis wrote:
On Tue, 11 Aug 2015 02:35:01 -0700 (PDT)
xmetman wrote:

After listening to Carole Kirkwood talking about what a wet and cold
summer its been over Scotland this year on this mornings Breakfast
Weather, it does seem to me that as far as the media are concerned
most of today's weather woes in this country today, including this
one can be blamed on the jet stream, or lack of jet stream, or the
position of the jet stream. So if the answer to most of the world's
climate problems is the ubiquitous "jet stream", what about its part
in global warming? I haven't seen any research that looks into the
role jet streams play in global warming, but I'm sure it won't be
long before there is a slew of scientific papers about it.


There have been several suggestions that the differential warming of
the Arctic and the Tropics will weaken the Jet Stream due to a
reduction in thermal contrast. This weakening of the Jet would then
lead to large meanders in the Stream and long spells of severe
weather, either cold or hot. This idea seems to have been accepted
though it bothered me a bit when I actually started to think about it.

I recall being taught (which I accept does not necessarily mean I was
taught) that slow-moving or stationary upper waves are associated with
a strong Jet; small, transitory waves are associated with weak Jet
Streams.

Then I found an article by CEP Brooks in an online 1950 issue of
Weather which said more or less the same thing. It also said that
they'd expected a weakening of upper winds due to the differential
warming that had occurred before WWII and had been surprised to find
that they'd strengthened instead.


At lower levels in the atmosphere, the number of Atlantic gales affecting the UK has dropped significantly this century compared to much of the last century. THe winter of 2013/14 was exceptional, but even then not for the number of gales, more for the quite exceptional sea conditions in the SW largely, due to the unusual track of the depressions. (We got the seas normally reserved for western Ireland.)

At my site in Penzance there were an average of 14 gales per annum 19993-2002 - broadly in line with Lambs observations. The following 10 years saw an exceptionally low average of 5.5 per annum


One thing that has an effect on the atmospheric circulation, as I've
said before, is the pattern of SST anomalies, particularly in the Grand
Banks region.


--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]


I think that it's an easy option for the media to go back 1 step and blame everything on the Jet Stream. I agree that the SST anomalies have an influence, but this years N Atlantic SST anomalies can be blamed on the winds in that area over the late winter period. But what caused that anomalous set up? It's all about how far back you want to go.

Interesting area though

Graham
Penzance

[email protected] August 11th 15 02:11 PM

The answer is jet stream, now what's the question?
 
On Tuesday, August 11, 2015 at 12:45:34 PM UTC+1, Dawlish wrote:
On Tuesday, August 11, 2015 at 12:37:59 PM UTC+1, Alastair wrote:
"xmetman" wrote in message
...

I'm sure that the phrase "jet stream" will be cropping in many conversations
about the weather in the coming years, you can easily picture one old dear
saying to another in a bus queue "I know Enid the weather has been simply
terrible, and you know it's all down to the orientation of the Jet stream
over Iceland you know".

=========================



I monitored the jet stream for a few months........


Idiot.


Why does monitoring the jet stream make him an idiot?

Col


Dawlish August 11th 15 03:16 PM

The answer is jet stream, now what's the question?
 
On Tuesday, August 11, 2015 at 2:11:41 PM UTC+1, wrote:
On Tuesday, August 11, 2015 at 12:45:34 PM UTC+1, Dawlish wrote:
On Tuesday, August 11, 2015 at 12:37:59 PM UTC+1, Alastair wrote:
"xmetman" wrote in message
...

I'm sure that the phrase "jet stream" will be cropping in many conversations
about the weather in the coming years, you can easily picture one old dear
saying to another in a bus queue "I know Enid the weather has been simply
terrible, and you know it's all down to the orientation of the Jet stream
over Iceland you know".

=========================



I monitored the jet stream for a few months........


Idiot.


Why does monitoring the jet stream make him an idiot?

Col


From the science he has shown in the last week, regarding thermodynamics and centrifugal force, I would not be surprised if 'monitoring the jet stream' meant playing in the local beck with his toys.

There really are idiots, Col and this one is one.

Tudor Hughes August 11th 15 03:46 PM

The answer is jet stream, now what's the question?
 
On Tuesday, 11 August 2015 15:16:11 UTC+1, Dawlish wrote:
On Tuesday, August 11, 2015 at 2:11:41 PM UTC+1, wrote:
On Tuesday, August 11, 2015 at 12:45:34 PM UTC+1, Dawlish wrote:
On Tuesday, August 11, 2015 at 12:37:59 PM UTC+1, Alastair wrote:
"xmetman" wrote in message
...

I'm sure that the phrase "jet stream" will be cropping in many conversations
about the weather in the coming years, you can easily picture one old dear
saying to another in a bus queue "I know Enid the weather has been simply
terrible, and you know it's all down to the orientation of the Jet stream
over Iceland you know".

=========================


I monitored the jet stream for a few months........

Idiot.


Why does monitoring the jet stream make him an idiot?

Col


From the science he has shown in the last week, regarding thermodynamics and centrifugal force, I would not be surprised if 'monitoring the jet stream' meant playing in the local beck with his toys.

There really are idiots, Col and this one is one.


Dear me, you're not a happy bunny, are you? What's up, then? Tell Uncle T (my nieces' appellation).

Tudor Hughes, Warlingham, Surrey.


Tudor Hughes August 11th 15 04:17 PM

The answer is jet stream, now what's the question?
 
On Tuesday, 11 August 2015 13:10:19 UTC+1, Graham Easterling wrote:
On Tuesday, August 11, 2015 at 11:46:00 AM UTC+1, Graham P Davis wrote:
On Tue, 11 Aug 2015 02:35:01 -0700 (PDT)
xmetman wrote:

After listening to Carole Kirkwood talking about what a wet and cold
summer its been over Scotland this year on this mornings Breakfast
Weather, it does seem to me that as far as the media are concerned
most of today's weather woes in this country today, including this
one can be blamed on the jet stream, or lack of jet stream, or the
position of the jet stream. So if the answer to most of the world's
climate problems is the ubiquitous "jet stream", what about its part
in global warming? I haven't seen any research that looks into the
role jet streams play in global warming, but I'm sure it won't be
long before there is a slew of scientific papers about it.


There have been several suggestions that the differential warming of
the Arctic and the Tropics will weaken the Jet Stream due to a
reduction in thermal contrast. This weakening of the Jet would then
lead to large meanders in the Stream and long spells of severe
weather, either cold or hot. This idea seems to have been accepted
though it bothered me a bit when I actually started to think about it.

I recall being taught (which I accept does not necessarily mean I was
taught) that slow-moving or stationary upper waves are associated with
a strong Jet; small, transitory waves are associated with weak Jet
Streams.

Then I found an article by CEP Brooks in an online 1950 issue of
Weather which said more or less the same thing. It also said that
they'd expected a weakening of upper winds due to the differential
warming that had occurred before WWII and had been surprised to find
that they'd strengthened instead.


At lower levels in the atmosphere, the number of Atlantic gales affecting the UK has dropped significantly this century compared to much of the last century. THe winter of 2013/14 was exceptional, but even then not for the number of gales, more for the quite exceptional sea conditions in the SW largely, due to the unusual track of the depressions. (We got the seas normally reserved for western Ireland.)

At my site in Penzance there were an average of 14 gales per annum 19993-2002 - broadly in line with Lambs observations. The following 10 years saw an exceptionally low average of 5.5 per annum


One thing that has an effect on the atmospheric circulation, as I've
said before, is the pattern of SST anomalies, particularly in the Grand
Banks region.


--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]


I think that it's an easy option for the media to go back 1 step and blame everything on the Jet Stream. I agree that the SST anomalies have an influence, but this years N Atlantic SST anomalies can be blamed on the winds in that area over the late winter period. But what caused that anomalous set up? It's all about how far back you want to go.

Interesting area though

Graham
Penzance


I think you've mentioned this before, Graham, and to me it seems very significant but not well known. Do other places in the UK show a similar trend? The current orthodoxy among non-scientists, especially journalists, is that it's going to get stormier and that is going to cause all manner of dire effects. I even have a friend (he stood for the Greens in a local election) who insists this is what will happen. It seems that even the Good Guys have their fundamentalists and very tiresome they can be.
One study I have seen predicts the jet stream will move north but could actually be stronger in certain zones. Overall it seemed that the mean wind speed in the UK would be little changed.

Tudor Hughes, Warlingham, Surrey.



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