Air samples collected in Finland beginning during the Cold War may help unlock answers to climate change, according to researchers at Clarkson University.

The Soviet Union conducted weapons tests in the Arctic during the Cold War’s nuclear arms race. The Finnish Meteorological Institute began collecting weekly air samples in Kevo, 40 kilometers south of the Norwegian border, to determine the amounts of radioactivity that landed there from the Soviet Union’s nuclear test facilities. The Finns continued sampling long after a 1963 treaty banned such tests.

A team of Clarkson researchers is analyzing more than 2,300 weekly air samples from 1964, the first year the Finns archived the filters, through 2010; it is the largest such study ever conducted.

The analysis will allow climate researchers to better determine what particles were in the air as temperatures near the Arctic Circle warmed over the last five decades, according to Professor Philip K. Hopke, director of the Center for Air Resources Engineering and Science at Clarkson.

Clarkson University
James Laing (above), a Clarkson University Ph.D. student, is analyzing thousands of air filters collected in Finland that date back to the 1960s. These samples will provide global climate researchers with a more complete picture of the air near the Arctic Circle as temperatures rose there over the last half-century. Photo credit: Clarkson University

Hopke obtained the air samples through his collaboration with the Finnish Meteorological Institute.

“The more data you have, the more chance you have to discover something you didn’t know,” Hopke said. “Models only have in them what you know about. These kinds of archives are our only lead into the past.”

These analyses have exposed differences from before and after the Soviet Union’s demise, Hopke said. Concentrations of black carbon and heavy metals dropped, once the Soviet Union collapsed and its metal processing facilities shut down.

Lead levels substantially dropped during the same time period, according to graduate student James Laing, who is studying for his Ph.D. in environmental science from Clarkson and researching the project alongside Hopke. The drop in lead correlates with the gradual phase-out of leaded gasoline in Europe.

When the project is finished, global climate change modelers will have a more complete picture of the air near the Arctic Circle over the last 50 years, Laing said.

“The Arctic is warming a lot faster than anywhere else on Earth. We were having trouble modeling and explaining why,” said Laing. “We’ll be able to see if there are changes in specific types of pollution.”

A video of the research can be viewed at

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