Satellite measurements of large‐scale air pollution: Measurements of forest fire smoke

The transport, optical properties, total mass, and removal of smoke produced by forest fires in western Canada during late July and early August 1982 are studied using NOAA 7 Advanced Very High Resolution Radiometer (AVHRR) data. Color composite imagery is produced to track the movement of the smoke over Canada and the United States as the smoke traveled thousands of kilometers from the source region. Smoke optical thickness, particle size, and single scattering albedo (ratio of particle scattering to extinction) are computed using radiances measured by AVHRR bands 1 (0.58–0.68 μm) and 2 (0.72–1.10 μm). Results show that smoke optical thickness ranged from less than 0.1 greater than 3.7 and the geometric mean mass radii ranged from 0.3 to 0.9 μm. The smoke single scattering albedo ranged from 0.9 to nearly 1.0. The total smoke mass over the eastern United States, computed using the derived particle size and optical thickness, ranged from 0.1 to 0.5 Tg which is close to the 0.5 Tg estimated to have been produced by the fires based on the forest fuel content. The smoke lifetime is estimated to be between 15 and 20 days.