"The international definition of fog consists of a suspended collection of water droplets or ice crystal near the Earth's surface ..." Fog and Boundary Layer Clouds: Fog Visibility and Forecasting. Gultepe, Ismail, ed. Reprint from Pure and Applied Geophysics Vol 164 (2007) No. 6-7. பன்னாட்டுத் தரப்புத்தக எண்978-3-7643-8418-0. p. 1126; see Google Books Accessed 2010-08-01.
Use of the term "fog" to mean any cloud that is at or near the Earth's surface can result in ambiguity as when, for example, a stratocumulus cloud covers a mountaintop. An observer on the mountain may say that he or she is in a fog, however, to outside observers a cloud is covering the mountain. "Standard practice for the design and operation of supercooled fog dispersal projects" Thomas, P. (2005) p. 3. பன்னாட்டுத் தரப்புத்தக எண்0-7844-0795-9 See Google Books. Accessed 2010-08-01. Further distinguishing the terms, fog rarely results in rain, while clouds are the common source of rain.
