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Posted
  • Location: Stanwell(south side of Heathrow Ap)
  • Weather Preferences: Thunderstorms, squally fronts, snow, frost, very mild if no snow or frost
  • Location: Stanwell(south side of Heathrow Ap)

    Radio 4 - text from audio (Costing the Earth programme)

    Quote" Some of the factors that are important that we have now identified are things like the el Niño/laNina cycle in the tropical pacific, that sounds like it's a long way from Europe but it’s a very big disturbance in the climate system, when you have an el-Niño where the tropical pacific warms up or a la-Nina where it cools down, so when you get an el-Niño you get this wave that propagates out right across the globe affecting the northern hemisphere, and in ultimately having an influence on Europe and the UK, another factor is Arctic ice; we believe that when the ice is much reduced due to either the long term trend due to global warming or natural fluctuations, and this also tends to drive easterly winds in winter over Europe, that’s Still a research topic, but people are reasonably confident that’s what happens, and of course recent years we’ve had very low Arctic ice, which again is another indicator, and a very new factor that’s been identified is fluctuations in the suns output, every eleven years or so the sun goes through a cycle of high and low output, it’s quite a suttle thing, there are only small changes in energy, much smaller for example then the power you get out of a single light bulb in each square meter, but what we’ve had recently found is that the ultra violet light is fluctuating by more than previously thought, the ultra violet light is what heats the upper atmosphere where the ozone is, when there is less ultra violet and there is less heating so the tropical region in particular is a little bit cooler than normal, just a couple of degrees, and that means that the winds start to flow a bit more from the east, because the temperatures and the winds are imbalanced in the atmosphere, and then as we approach winter those easterly winds grow and descend through atmosphere until they get down to about the region where you take your commercial air flight a few miles above the surface and at this point they seem to affect the Jet stream in the Atlantic, they send it further south and they weaken it, and that change in the weather region in the lower part of the Atmosphere is what drives winds from Siberia, and bringing us the cold weather to Europe and the UK, so at solar minimum and a weak solar output you tend to get more winters that are colder and Easterly, we had low solar activity and we had very low Arctic sea ice, and we had an el-Niño, all of those things we think helped to drive easterly and cold condition over northern Europe and the UK.

    Looking at 2010/11 last winter then the el-Niño/la-Nina cycle had flipped, we were in the la-Nina

    phase that tends to give milder ends to winter, however the solar was still at low activity, the sun was

    still and the Arctic ice was very low again, so those two become driving more easterly conditions.

    Whats not possible is to predict the exact weather on a particular day months ahead, so for example

    we couldn’t currently say whether or not it’s going to snow on the 15th of January,

    however what we think might be possible is to say something about the average conditions over the coming months, so we can say whether or not it’s likely to be warmer or cooler than normal, if you look at the change in some of the drivers that we’ve been talking about you can start to build up some sort of a picture, the Arctic ice continues its general decline, this year it was the second lowest on record, so again that’s very low, that’s an important factor that drives easterly’s, the el-Niño/la-Nina cycle is now approaching a la-Nina for this winter, were very confident about that, that tends to drive a mild end to winter and perhaps a colder start, it’s not as strong as last years i might say though, only one or so degree below normal compared to two degrees, so its twice as strong last winter, and the solar factor is now on the rise, were getting pretty close to sort of average conditions for the solar activity, so that is less likely to be a factor as it has been in recent winters."

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    Posted
  • Location: Stanwell(south side of Heathrow Ap)
  • Weather Preferences: Thunderstorms, squally fronts, snow, frost, very mild if no snow or frost
  • Location: Stanwell(south side of Heathrow Ap)

    So there it is the text from the radio 4 BBC interview that everyone was talking about in the winter forecast thread!

    http://www.bbc.co.uk...rammes/b01685zk - this is the link of the full 30 minute programme.

    The part i have extracted is an interview with a scientist/meteorologist from the MetOffice, on the factors that are the possible causes of our recent cold winters, La-Nina, solar activity, jet stream, Arctic sea ice.

    It took me a long time to do this and it is accurate by the word, and have checked it.

    This radio program was especially interesting to me, it puts foward much of what i and many others has been saying for quite sometime, i really enjoyed listening to it!

    smile.png

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    Posted
  • Location: Purley, Surrey - 246 Ft ASL
  • Weather Preferences: January 1987 / July 2006
  • Location: Purley, Surrey - 246 Ft ASL

    The interesting thing to take from that is the MetO do not think that solar activity has a lag effect.

    I think they are a bit naiive, this cycle is not average compared to previous ones, it is expected to be low and cycle 25 could be even lower.

    I think there must be some head scratching going on at MetO HQ.

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    and the solar factor is now on the rise, were getting pretty close to sort of average conditions for the solar activity, so that is less likely to be a factor as it has been in recent winters."

    that seems to be what RD is using to suggest that they are not really clued up!

    I suggest you have taken it rather out of context mate? What he says does not, to me, suggest what you say. All he has said, quoting the text kindly given us by ESS, is that its less likely to be a factor, perhaps had he said such a major factor might have been better. But try being interviewed by the media after a certain angle and managing to get everything you want to say actually said-not easy I can assure you from personal experience with the media.

    I think to suggest that the head of the research side of the Met O lrf team or whatever title he has is naiive is a bit rich but true enough we are all entitled to our opinions.

    Like I posted last evening its good to see that what was looked upon as 'heresy' in the official meteorological world is now accepted as part of the equation in trying to produce meaningful seasonal forecasts.

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    Posted
  • Location: Purley, Surrey - 246 Ft ASL
  • Weather Preferences: January 1987 / July 2006
  • Location: Purley, Surrey - 246 Ft ASL

    and the solar factor is now on the rise, were getting pretty close to sort of average conditions for the solar activity, so that is less likely to be a factor as it has been in recent winters."

    that seems to be what RD is using to suggest that they are not really clued up!

    I suggest you have taken it rather out of context mate? What he says does not, to me, suggest what you say. All he has said, quoting the text kindly given us by ESS, is that its less likely to be a factor, perhaps had he said such a major factor might have been better. But try being interviewed by the media after a certain angle and managing to get everything you want to say actually said-not easy I can assure you from personal experience with the media.

    I think to suggest that the head of the research side of the Met O lrf team or whatever title he has is naiive is a bit rich but true enough we are all entitled to our opinions.

    Like I posted last evening its good to see that what was looked upon as 'heresy' in the official meteorological world is now accepted as part of the equation in trying to produce meaningful seasonal forecasts.

    I am not suggesting they are not clued up, but they must be scratching their heads a little bit. I do not believe that in 2008 they saw what was coming in regards to the winters that have followed.

    I just think that in the context of the solar cycles of the last century (especially the end of the century) that Cycle 24 cannot be described as normal. Though reading it again, perhaps he is meaning that sunspot numbers have now recovered from where they were (which was zero for a long time).

    I meant no offence, but I think there is nothing wrong with a little criticism now and again.

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    Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

    Having read the piece posted by ESS, my take is the MO are going for a greater chance of another colder than average Winter, with the same pattern as the last one, i.e coldest early, mildest late. They appear to suggest that many of the driver are still in place, but a weaker La Nina and slowly increasing solar activity (despite the lag) may well ensure things are not as severe... at least that is the inference I get, but perhaps I'm reading it wrong...search.gif Let's face it, in typical MO stylee he was as clear as mud...lazy.gif

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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    I meant no offence, but I think there is nothing wrong with a little criticism now and again.

    none taken RD and they do deserve a critical comment about how long it seems to have taken them to take on board some teleconnections

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    Posted
  • Location: Stanwell(south side of Heathrow Ap)
  • Weather Preferences: Thunderstorms, squally fronts, snow, frost, very mild if no snow or frost
  • Location: Stanwell(south side of Heathrow Ap)

    Thanks for the replies everyone, im interested in the solar/jet stream interactions.

    Just found some info on the solar/cold winter and mentions the Jet stream

    (Published online 14 April 2010 )

    Ebbing sunspot activity makes Europe freeze

    350 years of data link low solar activity to cold winters.

    Richard A. Lovett

    A quieter sun means colder winters for Europe.

    Periods of low sunspot activity are associated with changes in the winds that tear though the upper atmosphere, bringing unusually cold winters to northern Europe, a new study finds.

    The study, published today in Environmental Research Letters1, analysed 350 years of temperature data recorded in central England since 1659, comparing it to astronomical observations of sunspots. The research team, led by Mike Lockwood, a solar-terrestrial physicist at the University of Reading, UK, found that after allowing for global climate change, European winters tended to be 0.5 °C colder than average during low-solar-activity years.

    The effect is pronounced enough, he says, that the winter of 2009 was England's 18th coldest in the past 350 years, even though global temperatures were at their fifth highest.

    "It is a very careful statistical analysis, which is not the case with all the papers in this particular subject area," says Joanna Haigh, an atmospheric physicist at Imperial College London.

    It is less clear why changes in solar activity can affect weather patterns.

    Light effect

    Lockwood says that the pattern is related to the effect of ultraviolet light on Earth's stratosphere, located about 20–50 kilometres above the surface. Ultraviolet light from the Sun is absorbed by ozone in the stratosphere, protecting the planet's surface but heating the stratosphere in the process. The effect is largest in the tropics, where sunlight is strongest, and the temperature gradients set up a global pattern of upper-atmosphere winds, including the Northern and Southern Hemisphere jet streams.

    "Relatively simple models have demonstrated that heating the equatorial stratosphere can push the jet streams apart just a little bit," says Lockwood. Similarly, cooling the stratosphere — as occurs during periods of low solar activity — allows the jet streams to shift towards the Equator. This, he says, seems to have a profound effect on European weather by causing the northern jet stream to block warm maritime air from reaching the continent from the Atlantic Ocean. This, in turn, opens the door to cold, northeasterly winds from Russia and the Arctic.

    It is a pattern seen in weather records from as far back as 1650–1700, an era known as the Maunder minimum, when the Sun was virtually sunspot-free and 'frost fairs' were held on the River Thames in London. "Early instrumental records show that those cold winters were accompanied by cold winds from the east," says Lockwood. Similar wind patterns can be deduced from looking at records of wine harvests in Europe, he adds.

    Not that these correlations are perfect. "The winter of 1684 was the coldest in the whole record," says Lockwood. "But the very next year, when solar activity was still low, was the third warmest."

    European phenomenon

    Part of the variability might be due to factors not taken into account in the paper, suggests Judith Lean, a solar-terrestrial scientist at the US Naval Research Laboratory in Washington DC. For example, she notes that the paper didn't take into account volcanic eruptions, even though these can influence European weather. Still, she says, it is a good study, demonstrating how the complex dynamics of global climate can be 'tweaked' by changes in solar activity.

    Lockwood is quick to point out that even if the recent lull in sunspot activity extends into another Maunder minimum, the effects are regional and it will not offset global warming. "This is very much a European phenomenon," he says.

    Still, he says that there is a chance that Europe can expect more chilly winters. "The Sun has been unusually active for the past few decades and is now declining towards average or even low-activity levels," he says. But he argues that the best way to determine the long-term trend isn't simply to count sunspots. Instead, he says, it is better to look for the changes in the underlying solar magnetic field that drives the flares and sunspots that produce increased levels of ultraviolet activity.

    "At each sunspot minimum, the Sun is wiped almost completely clean of spots, which gives the impression that the Sun repeatedly returns to the same low activity state every 11 years or so," he says. "The solar magnetic field shows that this is not the case and that solar outputs at sunspot minimum can show considerable change."

    Lean disagrees. "I don't think irradiance is any lower now than in prior minima," she says, adding that the Sun is already beginning a new cycle of activity.

    Still, she says, "this is all healthy ongoing research". And, she adds, the basic finding that solar activity influences European winters seems to be spot on.

    http://www.nature.co...s.2010.184.html - link to above quote

    The below link is written by scientists(including Mr Lockwood) looking at the solar/cold winter factors.

    its a very long read and yet to read it all! ive included a PDF file to.

    http://iopscience.io...024001/fulltext - Are cold winters in Europe associated with low solar activity? also in PDF here - 1748-9326_5_2_024001.pdf

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