Radar probes pollution damage

The aurora over Svalbard at noon in early January (Photo: D.A.R.Simmons)

By environment correspondent Alex Kirby in Longyearben, Svalbard

Scientists on an Arctic mountaintop studying pollution in the upper atmosphere believe it may be changing the Earth's protective systems.

But their leader says he cannot afford to run his sophisticated radar array long enough to collect all the data that is needed to complete the study.

The radar is already obtaining data that could be collected nowhere else on Earth.

The array, on a peak near Longyearben in Svalbard, Norway's Arctic archipelago, is part of Eiscat - the European Incoherent Scatter Scientific Association.

The technique relies on the scattering of radio waves from the incoherent motions of the electrons in the ionosphere.

Establishing trends

Eiscat, whose members are Finland, France, Germany, Japan, Norway, Sweden and the UK, has radar installations in several countries.

The project's leader, its science director, Tony van Eyken, from the United Kingdom, says his team needs to be able to amass enough data to establish clear trends.

The ESR mobile antenna

The Svalbard radar costs £300,000 a year to run. Tony van Eyken told BBC News Online: "If I had more cash, I'd run more.

"We have all this equipment, and we run for 1,000 hours annually. I'd run for 3,000 hours if I could, and it would be infinitely more useful.

"In September I'll run the array 24 hours a day for 16 consecutive days, the longest stretch ever. Running for longer gives you trends, not just snapshots."

Eiscat says: "There are indications that the upper atmosphere is very sensitive to environmental changes resulting from man-made pollutants transported upwards from the biosphere.

"This could have an influence on the shielding properties of the upper atmosphere. Consequently, there may be a feedback effect on the biosphere."

Echoes found

Tony van Eyken says this refers to noctilucent clouds, which shine at night and are found at up to 85 km above the Earth: "Nobody understands what causes them to form.

Tony van Eyken wants to do more

"Probably they form around dust particles. But there's no record of them being seen before the 1880s, although they are more visible than the aurora, which is described in the records.

"So the supposition is that they're the result of industrial pollution. We're finding strong echoes close to where they are.

"What we don't know is what effect they may be having there, and possibly on the Earth's surface."

The Eiscat Svalbard Radar, ESR, began work in 1996, making improved measurements of the ionosphere and atmosphere at high latitudes in the polar cap, as well as of the coupling with the magnetosphere and the solar wind.

Optimum location

Eiscat says the ESR's observations "will lead to major advances in the understanding of the whole chain of solar-terrestrial relations".

Svalbard is the ideal choice for the ESR. The sunward side of the auroral oval, the region where the Northern Lights can be seen, and the cusp in the Earth's magnetic wind are usually at magnetic latitudes around 70 to 80 degrees.

"Svalbard is at the optimum location for ground-based instrumentation to study the magnetosphere-ionosphere interactions in this region."

Tony van Eyken is proud of the sophistication of the ESR array, which comprises a 32-metre mobile antenna and a 42-metre fixed one. "They can detect a Stealth aircraft-sized object at the distance the US is from here," he says.

"This is a very bright beacon for any civilisation that may be out there. Switching it on is a bit like going out into the jungle and making a lot of noise, and wondering who's going to come and eat you."