Many years of cold winters lie ahead

Tue, Nov 30, 2010, 00:00

CLIMATE:WE ARE likely to experience several years of colder winters with more frequent cold spells similar to the current conditions, according to a UK climate expert.

The change comes as a result of a link between the sun and the high altitude jet stream winds, explained Prof Mike Lockwood of the department of meteorology at the University of Reading.

He and colleagues have established a link between low solar activity and a phenomenon known as “jet stream blocking”.

It causes a change in the normal weather patterns, keeping warmer Atlantic air away and instead channelling frigid Arctic and Siberian air across western Europe, including Ireland, he said.

“It looked last week like we had a blocking event formed,” he said. “The phenomenon is really a snaking of the jet stream. It can start to pull lower altitude, cold Russian air back in over Europe.”

Solar activity in this case does not mean heat or light from the sun but the energy emitted from the solar surface by sunspots.

This affects the upper atmosphere, which in turn influences conditions closer to the ground.

Prof Lockwood, who is also based at the Rutherford Appleton Laboratories in Oxfordshire, has shown that historically when sunspot activity is low, the jet stream changes direction to bring on the freezing weather.

The sun is currently very quiet, having recently passed through the “solar minimum”, the low point in an 11-year solar cycle that peaks at the “solar maximum”.

This will lead to more cold spells in the next few months and years, he believes.

“November is a pretty good predictor of what December through February is going to be like,” he said.

Yet while stockpiling of road grit may have to continue for the next few years, these conditions did not mean that climate change was over, Prof Lockwood warned.

“The big thing people need to appreciate is the weather they experience on a local or a regional scale is not the same thing as global temperatures,” he said.

“Our colder winters mean almost nothing in terms of global averages. That is why climate change is a better term than global warming.”