Form of precipitation where water drips to the ground from trees, bushes, or other objects which have collected moisture from fog.
In the Pacific Northwest, where coniferous forests are situtated in fog-prone coastal areas and which have needles to provide numerous points for condensation, it is estimated that up to 35% of an old growth forest's precipitation is attributed to fog drip (Researchers can distinguish the chemical signature of fog from rain water due to their differing ratios of stable hydrogen isotopes). In fact, some trees are dependent upon fog drip-- most notably the California redwood, Sequoia sempervirens, which is restricted in its range to the foggy areas of northern California and southern Oregon. Plants in the understory of redwoods, such as sword ferns, are sometimes 100% dependent on fog drips for water during the summer months.
Since 1992, the village of Chungungo in Chile, located in a coastal desert, has used fog drip as steady supply of water, thanks to polypropylene mesh fog collectors.
Tod E. Dawson. " The Use Of Fog Precipitation By Plants In Coastal Redwood Forests." Conference on Coast Redwood Forest Ecology and Management
. <http://www.cnr.berkeley.edu/~jleblanc/WWW/Redwood/rdwd-The-4.html> (19 August 2004)
Pattie LaCroix. "Clouds on Tap: Havesting Fog Around the World." International Development Research Centre Reports.16 October 1998. <http://web.idrc.ca/en/ev-5077-201-1-DO_TOPIC.html> (19 August 20004)
"fog drip," Glossary of Meteorology, second edition. <http://amsglossary.allenpress.com/glossary/browse?s=f&p=26> (19 August 2004)
Robert Meyers, Jim Botti, et. al. "Precipitation and Water Supply." Exploring the Environment. 4 June 2003. <http://www.cotf.edu/ete/modules/temprain/trprecip.html> (19 August 2004)