Aerosol measurements in central Alaska, 1982–1984

Atmospheric aerosols in subarctic central Alaska were studied for two winter seasons. Both optical absorptivity and excess (non-marine) sulfate undergo seasonal variation similar to that reported in Arctic locations (maximum in late spring and minimum in summer), but the magnitudes are a factor of two smaller than in the Arctic. The meridional variation in aerosol blackness and sulfur content (cleaner air to the south) is contrary to the trend in the Scandinavian Arctic and is interpreted to indicate the existence of pollution sources generally north and west, outside of Alaska's borders.