Uk Weather Predictability And The Effects Of The Jet-stream...

[Gray-Wolf]

The studies on the Jet's odd sinuosity does not negate it's northerly migration, it just over-rides the slowly , slowly pattern whilst the Arctic settles into it's new 'seasonal ice' setting. Imagine all the waters of the Arctic ocean open to warming over summer? what impact on the circulation then? We have seen the Barentsz/Kara papers (based on observations through the noughties) but we have no idea just how the pattern will be once we have that type of heat loss come early winter? (or do we???)

J' , I know you accept that the planet is warming but do you yet accept that the High Arctic is now at a point not seen since before the onset of the last ice age or do you still see the changes there as merely 'natural cycles'?

[jethro]

At no point have I endorsed the "Modern Winters" views of either Ian Brown or Stratos Ferric, their ideas were flawed, as I pointed out in the last post "This isn't speculation based on the last few years" - apologies if that wasn't clear

I've also never said that any one thing controls our weather.

Neither have I said that the paper I posted nullifies older studies in anyway. Those are straw man arguments.

The rapid warming of the Arctic has a clear influence on our weather and yes, it is but one of numerous factors that does so. Plenty of other drivers and variables will act to keep the weather quite changeable on a large scale. Nobody is claiming that Arctic warming is the dominant factor in our weather, but it has been demonstrated to be a contributing factor all the same.

There is nothing straw man about pointing out that many things affect the weather, neither is there anything even remotely straw man about reminding folk that previous conclusions have jumped the gun both in the world of climate science and on this forum. The origins of this thread lay in a discussion about weather patterns, how they have changed over the last 3-4 years and whether it is a symptom of climate change. The same questions were asked about the era of modern winters, conclusions were drawn which proved to be wrong. If we are to have a meaningful debate about this issue then IMO it would make more sense to approach it from a "what's going on" perspective rather than a "we know what's going on" perspective. The former approach tends to lead to more of an opportunity for us all to learn, the latter approach tends to descend very quickly into a two sided, them and us fiasco with the HUGE barrier of belief in climate change marching right down the middle. We've all been there, done that, countless times - it's dull for everyone.

The focus here thus far has been almost entirely upon the latest paper about the impact the ice levels may have, your previous post (22) demonstrated this by citing " a clear and proven relationship". There are clear and proven relationships about many things which affect our weather - the paper about Arctic ice is no more nor less important than many of the others, it's merely another possible piece in the puzzle. Personally speaking, I would be happier about accepting this clear and proven relationship if the Sun was more active than it currently is. From what I've seen and read, both lower ice levels and a quiet Sun can have a similar impact; currently we have no way of separating the signal from either in order to measure which is having the most impact.

[jethro]

J' , I know you accept that the planet is warming but do you yet accept that the High Arctic is now at a point not seen since before the onset of the last ice age or do you still see the changes there as merely 'natural cycles'?

My stance remains as it was GW - We've warmed in recent decades, some is undoubtedly down to changes we have made (not just CO2, land use changes, deforestation, ozone depletion etc) some of it is natural. Deciphering the percentage of warming which can be attributed to either cause is beyond our capabilities at the moment and will continue to be so for some considerable time.

Do I accept the "not seen since the last ice age" stuff? Not a hope. Not without a time machine or the ability to flit back and forth between the ages or an absolutely, bang on accurate crystal ball. Failing that, I'd settle for the ability to understand and measure the proxies (which ever you choose) and calibrate them to a degree which matches the modern measurements we have for temperature and ice levels. Proxies are best guesses IMO and like most things in life, open to interpretation. I can look into the sky and see all sorts of patterns and shapes in the clouds, you could be laying next to me, looking at exactly the same clouds and see another thing entirely.

I think this entire debate fails because in our efforts to decipher and understand the undecipherable and unknown, the human instinct of want takes over. We want, therefore we get. We want to know, so we settle for the little bit we do know with any degree of certainty, present it as fact and gloss over the huge unknowns still existing.

Then some irritating little sod like me comes along and says "ah but......"

[BornFromTheVoid]

There is nothing straw man about pointing out that many things affect the weather, neither is there anything even remotely straw man about reminding folk that previous conclusions have jumped the gun both in the world of climate science and on this forum.

You don't need to inform me. I clearly stated;

"This isn't speculation based on the last few years but instead, based on a very sound scientific foundation and observed evidence of upper atmospheric changes

At no point have I endorsed the "Modern Winters" views of either Ian Brown or Stratos Ferric, their ideas were flawed"

The origins of this thread lay in a discussion about weather patterns, how they have changed over the last 3-4 years and whether it is a symptom of climate change. The same questions were asked about the era of modern winters, conclusions were drawn which proved to be wrong.

And once more,

"This isn't speculation based on the last few years but instead, based on a very sound scientific foundation and observed evidence of upper atmospheric changes...

At no point have I endorsed the "Modern Winters" views of either Ian Brown or Stratos Ferric, their ideas were flawed"

So stop drawing this stuff into the debate, nobody agrees with, it was unscientific and thus nothing to do with this thread.

If we are to have a meaningful debate about this issue then IMO it would make more sense to approach it from a "what's going on" perspective rather than a "we know what's going on" perspective.

I still don't know why you're saying this to me when I said,

"I've also never said that any one thing controls our weather...

...The rapid warming of the Arctic has a clear influence on our weather and yes, it is but one of numerous factors that does so. Plenty of other drivers and variables will act to keep the weather quite changeable on a large scale. Nobody is claiming that Arctic warming is the dominant factor in our weather, but it has been demonstrated to be a contributing factor all the same."

The former approach tends to lead to more of an opportunity for us all to learn, the latter approach tends to descend very quickly into a two sided, them and us fiasco with the HUGE barrier of belief in climate change marching right down the middle. We've all been there, done that, countless times - it's dull for everyone.

Some of this I can agree with

The focus here thus far has been almost entirely upon the latest paper about the impact the ice levels may have, your previous post (22) demonstrated this by citing " a clear and proven relationship". There are clear and proven relationships about many things which affect our weather - the paper about Arctic ice is no more nor less important than many of the others, it's merely another possible piece in the puzzle.

I thought I was being clear:

"I've also never said that any one thing controls our weather...

...The rapid warming of the Arctic has a clear influence on our weather and yes, it is but one of numerous factors that does so. Plenty of other drivers and variables will act to keep the weather quite changeable on a large scale. Nobody is claiming that Arctic warming is the dominant factor in our weather, but it has been demonstrated to be a contributing factor all the same"

Personally speaking, I would be happier about accepting this clear and proven relationship if the Sun was more active than it currently is. From what I've seen and read, both lower ice levels and a quiet Sun can have a similar impact; currently we have no way of separating the signal from either in order to measure which is having the most impact.

The low solar activity of recent years has almost certainly played a role. The correlations are there, there is no doubting that. They have just yet to establish a proven mechanism for the for sun spot/ solar output warming. The Arctic has a clear and proven mechanism, linked with increased temperatures due to decreased ice and snow cover and the atmospheric affects they have, as you can read in the paper, or read the "In The News" read. The solar activity mechanism would most likely be different and discernible to that.

[jethro]

BFTV - stop shouting, there is no need, it adds nothing positive to this discussion.

You didn't start this thread, you are not the only one to have posted in it. My posts have been generalised ones, the parts that you particularly object to (the even larger teapot references) were in response to the original idea which sparked this thread. A few years of different weather doesn't necessarily indicate a climate shift - if it did, those who advocated the even larger teapot theory would more than likely have been proven right. You may not think it is relevant to this discussion, I disagree, it is a shining example of jumping to conclusions about weather and extrapolating it into climate. As this is an inclusive debate, open to all equally, and as it is relevant to the topic, I think it merits some thought. You are of course welcome to disagree but it's a bit off telling me to stop.

As for the Solar impact, it isn't possible to discern how much of the change is due to it, nor how much is due to ice cover. Knowing how the mechanism works for the ice cover doesn't answer that question. We know that changes in UV play a role and that ozone is also part of the equation - all things may be having an equal impact, or they may not - we just don't know. Until such time as we can un-scrabble that puzzle, all we can reliably say is that reduced ice cover is having some impact.

[BornFromTheVoid]

BFTV - stop shouting, there is no need, it adds nothing positive to this discussion.

You didn't start this thread, you are not the only one to have posted in it. My posts have been generalised ones, the parts that you particularly object to (the large teapot references) were in response to the original idea which sparked this thread. A few years of different weather doesn't necessarily indicate a climate shift - if it did, those who advocated the large teapot theory would more than likely have been proven right. You may not think it is relevant to this discussion, I disagree, it is a shining example of jumping to conclusions about weather and extrapolating it into climate. As this is an inclusive debate, open to all equally, and as it is relevant to the topic, I think it merits some thought. You are of course welcome to disagree but it's a bit off telling me to stop.

As for the Solar impact, it isn't possible to discern how much of the change is due to it, nor how much is due to ice cover. Knowing how the mechanism works for the ice cover doesn't answer that question. We know that changes in UV play a role and that ozone is also part of the equation - all things may be having an equal impact, or they may not - we just don't know. Until such time as we can un-scrabble that puzzle, all we can reliably say is that reduced ice cover is having some impact.

Clearly a large number of wires have gotten crossed somehwere here. Shouting? I don't know where you are seeing any of that.

I could reply to all the above again, but I'd just be repeating myself.

In conclusion:

Lots of things influence our weather, way too many to list out here. We recently discovered the mechanism by which Arctic changes influences our weather, a handy step in improving our knowledge, but far from the holy grail. We know there is a correlation with the sun (among may others), but have yet to determine the physical mechanism.

Our understanding appears to be improving, but there's a long way to go.

[Polar Maritime]

Climatology has received new contributions from other scientific fields, especially from astrophysics and astronomy. The most recent research in these fields now allows us to predict, with high accuracy, the increase and decrease of solar activity, according to the position of the Sun relative to the baricentre (centre of masses of the solar system), as the planets orbit around the Sun. It has been proved, beyond any doubt or speculation, that the sun's magnetic cycles have a decisive influence over important climatic events such as the El Niño Southern Oscillation (ENSO), the amount of cosmic rays entering Earth's atmosphere (which determines the formation of clouds), and other vital variables such as the North Atlantic Oscillation. All these powerful factors, interacting within a very complex system such as the atmosphere, makes the role of CO₂ as the main driving force behind global warming, each day more insignificant and meaningless.

http://mitosyfraudes.org/Calen/SolarWind.html

http://mitosyfraudes.org/Calen/NinoLand.html

http://mitosyfraudes.org/Calen2/Rhodes.html

This also exposes the useless futility of general circulation models, inefficient imitations of the Earth's climate used by the greenhouse industry in order to promote scare campaigns about the climatic future of the planet, trying to impose restrictive measures on fossil fuel users – with more geopolitical implications than any real intention to stop an unreal warming that has not happened, not shows any signs of ever happening.

[Robbie Garrett]

Quite interesting...

http://www.weatheraction.com/displayarticle.asp?a=451&c=5

[Devonian]

Quite interesting...

http://www.weatherac...e.asp?a=451&c=5

In an advert from a self publicist kind of way...

[Robbie Garrett]

I was just wondering, or more so thinking if the rest of the year comes in at Below average and the end of the year is December 2010 synoptic? will most believe global cooling?? Because that would mean 2 negative year CET's this decade. 2010>2020

[BornFromTheVoid]

If the globe records 2 below average years in quick succession, then maybe something might be up. But it would be perfectly normal for the CET to record a few below average years in a row without it meaning about the global trend.

So no, even if the rest of this year came in below average, I personally wouldn't think global cooling was occurring, just weather!

[Gray-Wolf]

Anyone wondering about 'below average' back to back low monthly temps should look at 1976 .....not a bad year for us but for the globe?

[Summer Sun]

A new blog from the Met Office regarding the wet spring and summer of 2012

There’s no disputing it has been a very disappointing summer so far in 2012 – with the wettest June for over a century followed up by a very wet start to July.

In fact, barring a warm and dry spell towards the end of May, the weather has been persistently dull and wet since April – which was also the wettest in records dating back to 1910.

Our weather here in the UK is complex and determined by many different factors, including the position of the jet stream.

This is the narrow band of fast moving winds which runs from west to east across the Atlantic high up in the atmosphere.

http://www.youtube.com/watch?v=GpsRQtk6IfM&feature=player_embedded

How does the jet stream affect UK weather?

Weather (or low pressure) systems bearing rain and unsettled conditions move across the Atlantic on a regular basis. The jet stream guides these systems, so its position is important for UK weather.

In summer, we would expect the jet stream to be north of the UK – dragging those weather systems away from our shores to give us relatively settled weather.

So far this year it has been to the south of the UK, guiding those systems straight to us. This is the position we’d normally expect the jet stream to be in during winter, when we are more accustomed to these wet conditions.

So why is the jet stream stuck so far south?

The jet stream, like our weather, is subject to natural variability – that is the random nature of our weather which means it is different from week, month or year to the next.

We expect it to move around and it has moved to the south of the UK in summertime many times before in the past. It has, however, been particularly persistent in holding that position this year – hence the prolonged unsettled weather.

This could be due to natural variability – a bad run of coincidence, if you will – but climate scientists are conducting ongoing research to see if there are other factors at play.

Changes in sea surface temperatures due to natural cycles may be playing a part, but there is more research to be done before anyone can establish how big a role they play.

Research has also suggested that reducing amounts of Arctic sea-ice could be affecting weather patterns, but more research needs to be done to confirm this link. Currently Arctic sea-ice is at a record low for this time of year.

Is climate change playing a role?

In the long term, most climate models project drier UK summers – but it is possible there could be other influences of a changing climate which could override that signal on shorter timescales.

If low levels of Arctic sea ice were found to be affecting the track of the jet stream, for example, this could be seen as linked to the warming of our climate – but this is currently an unknown.

The Met Office Hadley Centre, working with climate research centres around the world, is making strides in determining how the odds of extreme weather happening have been influenced by climate change.

However, it is very difficult to do this type of analysis with such highly variable rainfall events, so it may take many years before we could confirm how the odds of this summer’s wet weather happening have been altered by greenhouse gases.

We do know that the warmer air is, the more moisture it can hold. We have seen a global temperature increase of more than 0.7 deg C (since pre-industrial times) and this has led to an increase of about 4-5% in atmospheric moisture.

This means that when we do get unusual weather patterns such as we’re seeing now, it’s likely there will be more rainfall than the same patterns might have produced in the past. In short, it seems when it does rain, it is heavier.

Taking into account this effect, perhaps it’s not surprising new records like those for this April and June are being set. In fact, the wettest July and November in the records dating back to 1910 happened in 2009, making a total of four record wettest months in the past four years. If wet months occurred randomly, we would expect only one record to have been broken since 2006.

For temperature, April (2011), May (2008), July (2006), September (2006) are all recent warmest records. Again, this is much more frequent than would be expected if temperatures were not rising.

What about elsewhere in the world?

Looking at the bigger picture, the jet stream may be having an impact elsewhere in the northern hemisphere. It is stuck in a persistent pattern of waves, with one of these ‘waves’ taking it to the south of the UK.

The figure gives a picture of the upper level winds for the first week in July, but the wavy nature of the jet stream has been persistent throughout June.

Meanders of the jet north and south can be seen across the US, the Atlantic and into Europe.

While the wet weather in the UK has been under a southward meander of the jet stream, the recent Russian floods near the Black Sea appear to have been beneath the next trough to the east.

The US heat wave is also beneath a northward meander and a ridge of high pressure.

* This article has been written in collaboration with the Walker Institute for Climate System Research, University of Reading.

http://metofficenews...climate-change/

Edited July 12, 2012 by Summer Sun

[Guest]

My simple mind thinks that if the temperatures are rising, this means more heat and more heat means more energy, more energy means a bigger variety of weather with the storms producing more rain and more wind at times.

As for the jet stream I think it is an intelligent beast set out to show us how little we know and everytime we think we are getting near the answer it will throw something else, quite unexpected, at us.

[Waterspout]

My simple mind thinks that if the temperatures are rising, this means more heat and more heat means more energy, more energy means a bigger variety of weather with the storms producing more rain and more wind at times.

Well, technically speaking the temperature has not been rising or falling for almost 15 years now!

I don't know enough about Ice loss to know if the Southerly Tracking jet is due to this. Although I always thought the Weather is controlled from the Top Downwards, so I'd like to know the mechanism by which a Loss of Summer Ice (for a few weeks) can cause the Jet Stream to track Southerly in Winter (aka the two Severe Winters) and also the last 4 or 5 Summers.

I think it's more widely understood now that UV Output from the Sun strongly influences the Jet Stream due to well known physical mechanisms. (UV fell 30% from 2001 to 2006) As the Jet Stream was only discovered in the 40's any exact data on its past behaviour is limited, although I'd be interested to see a reconstruction of the Jet Stream based on proxies of historic weather patterns. I wonder if someone will do this work soon, I'd have thought it was essential in making any links to it's changing pattern, with any natural variabilty or any man made influences on it.

Edited July 20, 2012 by Waterspout

[Gray-Wolf]

Well, technically speaking the temperature has not been rising or falling for almost 15 years now!

I don't know enough about Ice loss to know if the Southerly Tracking jet is due to this. Although I always thought the Weather is controlled from the Top Downwards, so I'd like to know the mechanism by which a Loss of Summer Ice (for a few weeks) can cause the Jet Stream to track Southerly in Winter (aka the two Severe Winters) and also the last 4 or 5 Summers.

I think it's more widely understood now that UV Output from the Sun strongly influences the Jet Stream due to well known physical mechanisms. (UV fell 30% from 2001 to 2006) As the Jet Stream was only discovered in the 40's any exact data on its past behaviour is limited, although I'd be interested to see a reconstruction of the Jet Stream based on proxies of historic weather patterns. I wonder if someone will do this work soon, I'd have thought it was essential in making any links to it's changing pattern, with any natural variabilty or any man made influences on it.

Pull up a chair, watch the data, see if it makes sense?

EDIT: better still try this. Longer ,more detailed ,better links/

[Robbie Garrett]

Interesting video.

[Gray-Wolf]

If the loss of physical mass of the ice has an important role of freeing up energy early on in the season (by the towering masses of ice no longer being present to 'chill' any WAA that arrives in the early melt season) then impacts on the jet could begin occuring ever earlier?

We have seen , so far this winter, the inability of the Arctic ocean to hold onto the type of cold it used to and again witnessed the failure of ice to form in Barrentsz/Kara. These two sea areas may play a pivitol role in allowing the Jet to become wayward once again this spring by presenting a lessened temp gradient to the equator from the moment the Arctic Sun rises again leading to altered circulation patterns? These 'altered patterns may prove fundimental in setting up the Southern Greenland H.P. system downstream and set the stage for increased sinuosity as the melt season progresses?

I still hold hopes that over time the sinuosity will increase and the frequency reduce leading to more 03/06 type summers for us here. I hope this mainly because we are still not up to full tilt with the Arctic Amplification and so as impacts become stronger and more pronounced. Greater rainfall events over the Central Atlantic has surely got to be a better deal over summer!!

[Gray-Wolf]

With the AO running dead opposite to recent winters so far I am wondering if this will manifest in a different pattern over summer?

Because I do see the Arctics role in the Jets positioning and strength I'd kind of hope for a return to a pre 06' jet (grand summer for us here!) or an even more extreme impact (in line with last years melt?) amplifying the jet and shortening it's wavelength (sorry Ireland) bringing us some of the continental blocking and warmth we've seen the near continent have whilst we've flooded over recent years?