haze, suspension in the atmosphere of minute dust or salt particles that are not individually seen but that nevertheless reduce visibility. So-called damp haze and dry haze produce different optical effects because the particles of each are of different sizes, with the dry haze particles being smaller. Damp haze may develop from dry haze when water condenses on moisture-absorbing dry haze particles. Continuation of this condensation leads to the formation of fog. A hazy condition often occurs in the summer and affects large areas from cities to mountains. Such a haze is often caused by excessive amounts of pollutants resulting from combustion; for example, the Smoky Mountain haze in Tennessee is ascribed to sulfate particles.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.

See more Encyclopedia articles on: Weather and Climate: Terms and Concepts