From Glossary of Meteorology


  1. Foreign particulate matter in the atmosphere resulting from combustion processes; a type of lithometeor.

    When smoke is present, the disk of the sun at sunrise and sunset appears very red, and during the daytime has a reddish tinge. Smoke that has come a great distance from its source, such as from forest fires, usually has a light grayish or bluish color and is evenly distributed in the upper air.
    See smog, haze.

  2. Applied to some types of fog.