The effect makes the Arctic 2 degrees to 3 degrees Fahrenheit warmer during polluted, cloudy episodes than it would be if the air was clean, concludes the study by Tim Garrett, an assistant professor of meteorology, and Chuanfeng Zhao, a doctoral student in meteorology.
"The Arctic is warming very quickly, especially compared with the rest of the world, due to the greenhouse effect caused by carbon dioxide from factories and cars," Garrett says.
"Now we are finding there is another way pollution can warm up the Arctic. Particulate pollution from factories and cars can be transported long distances to the Arctic, where it changes clouds so that they become more effective blankets, trapping more heat and further aggravating climate warming."
Arctic haze has been seen in the Arctic since the Industrial Revolution began about 1750. "Whalers and explorers noticed what looked like pollution and couldn't figure out where it was coming from," Garrett says. The Inuit (Eskimos) called it "poo-jok."
Scientists already knew particulate pollutants make clouds more effective at reflecting sunlight, which reduces surface temperatures. So the newly discovered effect is a surprise.
"What we found is an opposing effect where particulate pollution changes clouds so they warm the surface," Garrett says. "This effect is most pronounced in Arctic winter when it is dark and there is no sunlight. The Arctic winter is when it is most polluted because there is almost no precipitation to wash out the pollutants, and there also is a
Source:University of Utah