Clear link between solar activity and winter weather revealed

Scientists have demonstrated a clear link between the 11-year sun cycle and winter weather over the northern hemisphere for the first time.

They found that low solar activity can contribute to cold winters in the UK, northern Europe and parts of America. But high activity from the sun has the opposite effect.

The study helps explain why the UK has been gripped by such cold winters over the last few years: the sun is just emerging from a so-called , when solar activity is at its lowest.

'Our research establishes the link between the and winter climate as more than just coincidence,' says Dr Adam Scaife from the UK's Met Office, one of the study's authors.

The findings, published in Nature Geoscience also raise the tantalising possibility that the regularity of the solar cycle might help weathermen predict cold winter weather over the northern hemisphere.

'We've been able to reproduce a consistent , confirm how it works, and quantify it using a . This isn't the sole driver of winter climate over our region, but it is a significant factor and understanding it is important for seasonal to decadal forecasting,' says Scaife.

Up until now, researchers have only managed to see a weak link between solar activity and winter weather: when the sun is less active, we're more likely to see weak westerly winds during the winter in the . This pattern suggests that easterly winds could bring from the continent to the UK.

But scientists have struggled to incorporate these ultraviolet (UV) signals into climate models.

Now, new from NASA's and (SORCE) have revealed that differences in UV light reaching the Earth during the 11-year solar cycle are larger than previously thought. The satellite, launched in 2003, is the first ever to measure solar radiation across the entire UV spectrum.

'The instrument on the SORCE satellite divides UV light up into small wavelength regions, providing good spectral resolution. Before this, used broad spectral bands, so couldn't reveal the solar signal,' explains Professor of atmospheric physics, Joanna Haigh from Imperial College London.

Using this new information in a Met Office climate model, Scaife, Haigh, and other researchers from the Met Office and the University of Oxford, demonstrate that it's possible to reproduce the effects of solar variability which show up in climate records.

It seems that in years of low UV activity, unusually cold air forms over the tropics in the stratosphere, about 50 kilometres up. This is balanced by a more easterly flow of air over the mid latitudes – a pattern which then makes its way down to the Earth's surface, bringing easterly winds and to northern Europe.

But when is higher than usual – around the peak of the 11-year solar cycle – the opposite happens: strong westerly winds bring warm air and so milder winters to Europe.

'What we're seeing is UV levels affecting the distribution of air masses around the Atlantic basin. This causes a redistribution of heat – so while Europe and the US may be cooler, Canada and the Mediterranean will be warmer, and there is little direct impact on global temperatures,' explains Sarah Ineson from the Met Office, lead author of the report.

'Even with the most sophisticated atmospheric models, it is very hard to predict weather patterns on seasonal timescales. This study, along with our ongoing research through the NERC Solar Variability and Climate (SOLCLI) consortium, is adding much detail to our current understanding,' says Haigh.

She is keen to point out that this finding is based on just one satellite: 'If there's something wrong with the instrument we used to get this new data, this might not be right.'

Haigh is however, confident of the mechanism. 'While statistical data pointed to links between UV from the sun and winter weather, this new paper explains how those links come about,' she says.


This story is republished courtesy of Planet Earth online, a free, companion website to the award-winning magazine Planet Earth published and funded by the Natural Environment Research Council (NERC).

Explore further

Are winters in Europe becoming colder?

More information: Sarah Ineson, Adam A. Scaife, Jeff R. Knight, James C. Manners, Nick J. Dunstone, Lesley J. Gray and Joanna D. Haigh, Solar forcing of winter climate variability in the northern hemisphere, Nature Geoscience, published 9 October 2011, doi:10.1038/ngeo1282
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Citation: Clear link between solar activity and winter weather revealed (2011, October 10) retrieved 24 August 2019 from https://phys.org/news/2011-10-link-solar-winter-weather-revealed.html
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Oct 10, 2011
How does Piers Corbyn's method compare with this finding?

Hev
Oct 10, 2011
This was noticed by astronomers in the 17th century. At the time the Thames froze over in London, the winters were so cold, the astronomers could not find any sun-spots.

Oct 10, 2011
This does not prove the sun is a pulsar surrounded by a shell of waste helium and hydrogen. This does not prove the sun is powered by neutron repulsion. This does not prove some sort of global conspiracy to hide data to prevent nuclear war by making up global warming.

Oct 10, 2011
What isdarkdestruction said

Oct 10, 2011
How does this compare to Henrik Svensmark's theory about solar magnetic fields and cloud-cover ?
Why is the UV radiation lower when solar activity is lower ?

Oct 10, 2011
I hope my buy in Reynolds stock went through before Oliver got to the super market. He's definitely going to be afraid of the Bilderbergs now. lol

@Doug_Huffman

Aren't you one of the model deniers?

We've been able to reproduce a consistent climate pattern, confirm how it works, and quantify it using a computer model.


Seems like you're okay with models that confirm your bias.

AWT
Oct 10, 2011
Apparently, motion of Jupiter planet affects the location of center of mass of solar system, which affects the convection of solar plasma. When the center of mass appears beneath the Sun surface, the solar plasma doesn't circulate well and it tends to formation of bubbles (sun spots), solar bursts and solar flares.

Oct 10, 2011
Well, just in case the sunspots don't arrive in time for this Winter, we've bought urban crampons...

Oct 10, 2011
This does not prove the sun is a pulsar surrounded by a shell of waste helium and hydrogen. This does not prove the sun is powered by neutron repulsion. This does not prove some sort of global conspiracy to hide data to prevent nuclear war by making up global warming.
No but maybe this does
http://www.youtub...5OXfe9KY

Oct 10, 2011
too bad most of the other climate related satellites failed to launch, i wonder what science could do with more data rather than echo-chamber modeling

Oct 11, 2011
It's already been published that the main cause of climate change (in fact, the main weather promoter) is the Sun.
The difficulty is to get this in the minds and souls of those already hooked by the propaganda (sort of Goebbels' style) of the financially motivated weather alarmists.

GDM
Oct 11, 2011
I've always felt that the solar cycle was related to weather variations, but as I was instructed many years ago, the curiously similar contours between the continents, like Africa and S. America, were just "coincidence". Tectonics was not even a theory back then. Always nice to see science in action.

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