Temperature Inversions
Arctic Conditions
Arctic region inversions usually occur due to radiative cooling of lower layers. Advection occurs at a zone where warmer air is aloft over cooler heavier air below. Arctic inversions form either when warm air from inland is blown onto cold water or when cold snow covered surfaces are blown onto warmer water. Cold layers over valleys cover warmer advected air, creating strong inversions.
Temperature inversions prevent vertical air flow, which traps smoke and other pollutants from escaping into the atmosphere.
www.uaf.edu/seagrant/NewsMedia/01ASJ/12.14.01bad-air.html
Fairbanks Research
Fairbanks surface inversions can differentiate in temperature from higher aloft air by as much as 30-40 degrees Fahrenheit up to hundreds of feet above the ground. During December and January, surface inversions are visible in Fairbanks for more than 80% of the time day or night. Because the sun rises less than 3.5 degrees during these months, the temperature of the ground remains cold day and night. Interior Alaska with snow covered surfaces and prolonged darkness during the winter is prone to visible layers of trapped air pollution.