From the Institute of Physics
More than 1 in 10 chance of colder UK winters
As the Sun enters a period of low solar activity over the next 50 years, new research has calculated the probability of unusually cold winter temperatures occurring in the UK.
Last year, the same group of researchers, from the University of Reading, linked colder winters in Europe to low solar activity and predicted that the Sun is moving into a particularly low period of activity, meaning the UK will experience more cold winters in the future – potentially similar to those experienced in the Maunder minimum at the end of the 17th century.
The new research, published today, Tuesday 5 July 2011, in IOP Publishing’s journal Environmental Research Letters, supports recent suggestions that sunspot activity is waning, and goes further, using the behaviour of the Sun over the last 9300 years to predict the probabilities of future solar changes.
Over the next 50 years, the researchers show that the probability of the Sun returning to Maunder minimum conditions is about 10 per cent, raising the chances that the average winter temperature will fall below 2.5 oC to around 1 in 7, assuming all other factors, including man-made effects and El Niño, remain constant.
Put in context, the average UK winter temperature for the last 20 years has been 5.04 oC, however the last three winters have averaged 3.50 °C, 2.53 °C and 3.13 °C, with 2009/10 being the 14th coldest in the last 160 years.
The increased probability of colder winters could hold great value for national infrastructure planning by government organisations who have struggled to adapt to the extreme weather conditions experienced in the UK over the past two years.
It is stressed, however, that these results do not have any implications for global climate change, which is concerned with average temperatures for all parts of the world and all times of year. The reported changes only apply in winter and are regional – for example, when the winter is colder in Europe it tends to be warmer in Greenland so that there is almost no effect on the global mean.
These studies obtained the average temperatures between December and February for the past 352 years from the Central England Temperature (CET) data series – the world’s longest instrumental temperature record, maintained by the UK Met Office, extending back to 1659.
This data set was combined with records of the Sun’s activity obtained through the analysis of ‘cosmogenic isotopes’, which are specific types of carbon and beryllium that are known to be influenced by the Sun.
The magnetic field of the Sun protects the Earth from galactic cosmic rays, which, as they hit the Earth’s atmosphere, generate the cosmogenic isotopes which are then deposited in tree trunks and ice sheets. These cosmogenic isotopes can be collected and dated providing a unique insight into the Sun’s variability on timescales ranging from years to millennia.
Data from the cosmogenic isotopes suggests that we are currently coming to the end of a grand solar maximum – a period of intense activity in the Sun – and will therefore experience lower solar activity conditions in future,.
Many researchers have argued that temperature changes attributed to the Sun are, in reality, just caused by the internal variability of the climate system; however, the authors have used this 352-year temperature record to show that there is some, albeit small, predictive skill to be gained from solar activity despite it being just one of a number of factors that influence UK weather.
One mechanism that suggests a link between the Sun and recent cold winters is ‘blocking’. Low solar activity causes extensive anticyclones that persist for several weeks in the Atlantic Ocean, causing the warm westerly winds to be replaced by cold, continental north-easterly winds. Depending on the position of the anticyclone, this can also lead to clear skies at night causing the land to cool even further.
Lead author Professor Mike Lockwood said, “Our results show that over the next fifty years there is a 10 per cent chance that temperatures will return to Maunder minimum levels. Describing the Maunder minimum as a ‘little ice age’ is somewhat misleading however.
“Cold winters were indeed more common during the Maunder minimum but there were also some very warm ones between them, summers were not colder, and the drop in average temperatures was not nearly as great, nor as global, as during a real ice age.”
From Tuesday 5 July (when the link goes active) this journal paper can be found at http://iopscience.iop.org/1748-9326/6/3/034004
h/t to reader “a jones”
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rbateman asked:
“So how could a solar minimum force conditions colder overall for temperate to polar zones?”
Initially more meridional jets allow more air in and out of the poles. That starts by making the poles relatively warmer and mid latitudes relatively colder. However if it goes on long enough the colder mid latitudes reduce the warmth available for the poles so the poles start to get colder again too and eventually under a long term change to solar input such as the Milankovitch cycles an ice age will develop.
The reduced solar activity also causes more cloudiness by provoking more meridional jets so global albedo rises and less solar shortwave enters the oceans. Over long periods of time that too reduces the energy available to warm the poles and the mid latitudes.
So even without a large change in raw TSI a less active sun and/or a less effective solar insolation for astronomical reasons will eventually cool the entire system.
In the meantime the oceans have their own long term internal cycles responding to earlier solar variability. Sometimes they offset and sometimes supplement the effects of solar input changes. The ocean cycle phasing in relation to solar cycle phases will influence the timing of the switch from glaciation to interglacial and back again.
With current global landmass distribution I suspect that interglacials only occur for short periods when the solar and oceanic cycles are largely offsetting each others effects so as to reduce the size of climate swings from the extremes that prevail during glacial epochs.
It is large climate swings with deep cold winters and summers too short to melt so much ice that lead to ice buildups on the northern continents and to achive such large swings the solar and oceanic cycles need to be supplementing rather than offsetting one another.
“…It is stressed, however, that these results do not have any implications for global climate change, which is concerned with average temperatures for all parts of the world and all times of year. The reported changes only apply in winter and are regional – for example, when the winter is colder in Europe it tends to be warmer in Greenland so that there is almost no effect on the global mean…”
So the Vikings left Greenland as they couldn’t stand the heat? The glacier that pushed its way over their farmland was due to heat leading to more snow as well no doubt. /sarc
History shows that the cold was experienced over the entire northern hemisphere and there is evidence for cold in the southern hemisphere. But the hockey team have been desperately stating otherwise.
R.S.Brown – your first “Simple Solar link” may (inadvertently) be a bit of a cherry-pick as it shows only a decline. Over a longer period, cycle #24 looks like this
http://members.westnet.com.au/jonas1/SunspotGraph.JPG
Eyeballing the graph, I would say that we need to allow the sun at least till October to produce another surge in spots, before we worry overmuch about it failing. (But I am no expert, I have just graphed the numbers. Leif S may choose to give some insights???).
PS. Is there somewhere that produces a good daily sunspot count graph so I can stop doing it?
Mike Jonas says:
July 7, 2011 at 12:46 am
PS. Is there somewhere that produces a good daily sunspot count graph so I can stop doing it?
Here http://sidc.oma.be/html/wolfjmms.html and here http://www.leif.org/research/TSI-SORCE-2008-now.png
TBear (Warm Cave in Cold-as-Snow-Sydney) asked:
http://wattsupwiththat.com/2011/07/05/study-solar-activity-lull-increases-chances-of-cold-uk-winters/#comment-694435
“Why is so much attention being paid to this esoteric science?”
Mr. James Mill takes the principle that all men desire Power.
John Stuart Mill, assumes that all men desire Wealth mainly or solely.
Webster, in 17 U.S. 327 (1819), said: “An unlimited power to tax involves, necessarily, a power to destroy.”
Alfred’s Boethius: “Many men desire power, wishing to have good report, though they are unworthy of it; yea, even the most infamous desire this.”
Lord Acton (1887) says: “Power tends to corrupt, and absolute power corrupts absolutely.”
Pooh says he is a bear of little brain. What does he know?
There must be a proper debate about this. I have seldom observed so much division over a subject. The usual solution to debate publically, in a public forum, with experts on both sides giving thier opinion. Is it just me that believes the ABC so infiltrated by the left of politics that debate is refused? I for one do not like my mind being made up for me, as this is what is apparent when the prime minister says “the science is in” Entertaing films full of errors, do not settle science for me. The bias in the media is appalling, LET THE EXPERTS SPEAK FOR BOTH SIDES I WANT TO MAKE UP MY OWN MIND THANKYOU.