Climatology of High-Latitude Air Pollution as Illustrated by Fairbanks and Anchorage, Alaska

Sue Ann Bowling, Geophysical Institute and Department of Physics, University of Alaska, Fairbanks, AK 99775

High latitude communities frequently have severe air pollution problems. The usual situation is the release of moderate amounts of pollutants into an atmosphere with extremely poor dispersion. The poor dispersion is in turn a direct result of the high latitude radiation balance, which in winter is characterized by short days and low solar elevation. At locations north of 60 degrees N, the midwinter day length may vary from 0 to just under 6 hours, and at noon the sun, if it rises at all, is lower in the sky than it would be 45 minutes after sunrise in Los Angeles. The result is a ground based nighttime inversion which continues through peak traffic hours (throughout the day in some places), coupled with a complete lack of photochemical reactions. Downtown mixing heights as low as 10 m, combined with wind speeds less than 0.5 meters per second, have been measured in Fairbanks. If development at high latitudes is to proceed rationally, these meteorological conditions must be understood, and models developed that take account of them.

Full paper published 1986 in: Journal of Climate and Applied Meteorology 25, 22-34.