Air samples collected in Finland for 47 years since the beginning of the Cold War may help unlock answers to climate change, U.S. researchers say.

Scientists at Clarkson University in New York say they've analyzed air samples the Finnish Meteorological Institute began collecting weekly in 1946 as the Soviet Union conducted weapons tests in the arctic during the Cold War's nuclear arms race.

The analysis of more than 2,300 air samples from 1964 through 2010 will allow climate researchers to determine what particles were in the air as temperatures near the Arctic Circle warmed over the last five decades, a university release reported.

"The more data you have, the more chance you have to discover something you didn't know," Philip K. Hopke, director of the university's Center for Air Resources Engineering and Science, said. "Models only have in them what you know about. These kinds of archives are our only lead into the past."

The study will give global climate change modelers a more complete picture of the air near the Arctic Circle over the last 50 years, doctoral student James Laing said.

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

The analysis showed concentrations of black carbon and heavy metals dropped once the Soviet Union collapsed and its metal processing facilities shut down, the researchers said.

Lead levels substantially dropped during the same time period, they said said, correlating with the gradual phase-out of leaded gasoline in Europe.