A 'QUIET' period for sunspots and solar flares is providing high excitement for Oxfordshire scientists studying the sun.

But Prof Richard Harrison, of the Rutherford Appleton Laboratory, near Didcot, said the latest pictures from space telescopes were unlikely to provide any hope of a halt to global warming.

Sunspots – areas of intense magnetic fields that form on the sun’s surface – are the easiest way of measuring solar activity.

The number of sunspots in recent months has been the lowest since 1913. There has also been a 50-year low in solar wind pressure and a 55-year low in radio emissions.

Some people have suggested a dimming sun could help combat global warming.

But Prof Harrison said: “Some people will point to this as an effect on global warming, but the variations aren’t going to be significant, compared to the variation that we are causing by pouring extra carbon into the atmosphere.”

Speaking at this year’s National Astronomy Meeting in London, he said the sun’s current ‘quiet period’ meant space telescopes were producing exciting results.

“As astronomers we’ve never seen anything like this before in our lifetimes,” he said. “We have spacecraft up there to study the sun in phenomenal detail.

“We can study this minimum of activity in a way that we could not have done in the past.”

The Rutherford has one of the world’s leading solar physics groups, and has built several instruments which are now in space.

The laboratory has been receiving images from the Soho spacecraft for 14 years, while its latest experiment, in a satellite called Stereo, gives a side-on view as giant clouds of solar material leave the sun and slam into the magnetic field of the earth.

No-one knows how the centuries-long waxing and waning of the sun works, but it normally goes in 11-year cycles. Astronomers disagree about when the next ‘active’ stage will begin, but it is long overdue.

When it comes, the sun will bombard earth’s atmosphere with extra doses of solar radiation. The last peak, in 1989, caused power blackouts, knocked satellites out of orbit and disrupted radio communications.

Prof Harrison said: “From the 1600s to the 1700s, the sun was dramatically quiet.

“Some people are pointing to that, when there was a mini Ice Age, and suggesting it could happen again.

“The sun has certainly been quiet now for much longer than we would have expected.”

Last month, the European Space Agency announced that it would open a new centre next to the Rutherford site, creating up to 5,000 jobs.mhartford@oxfordmail.co.uk