Fog is really nothing more than a low-lying cloud, and usually occurs in a high-pressure area. There are about ten or more types of cloud classifications today. Here are the International Definitions:

1. Average altitude 9,000 meters (approximately 30,000 feet)
   • Cirrus - Cirrus clouds are nicknamed “feather” clouds because their wispy streams look like feathers, or sometimes even a horse’s tail. They appear with fair weather.
   • Cirruo-stratus
2. 3,000 - 7,000 meters (10,000 - 23,000 feet)
   • Cirro-cumulus
   • Alto-cumulus
   • Alto-stratus - These clouds are usually small masses, created by a combination of warm air near the ground and cooler air high in the atmosphere.
3. Below 2,000 meters (7,000 feet)
   • Strato-cumulus
   • Nimbus types
4. Diurnal ascending currents
   • Cumulus - Cumulus clouds form when the warm ground heats air and forms rising air currents. If the air rises too fast, however, the cumulus cloud may become a thunder-head or cumulo-numbus cloud.
   • Cumulo-nimbus
5. High fogs below 1,000 meters (3,000 feet)
   • Stratus - Meaning “layer” or “sheet,” these are flat, spread-out clouds.

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Forces of Nature: ThinkQuest 2000 (Team #C003603)

http://library.thinkquest.org/C003603/english/fogandmist/clouds.shtml [ f o g   &   m i s t   :   c l o u d s ]

Fog is really nothing more than a low-lying cloud, and usually occurs in a high-pressure area. There are about ten or more types of cloud classifications today. Here are the International Definitions:

1. Average altitude 9,000 meters (approximately 30,000 feet)
   • Cirrus - Cirrus clouds are nicknamed “feather” clouds because their wispy streams look like feathers, or sometimes even a horse’s tail. They appear with fair weather.
   • Cirruo-stratus
2. 3,000 - 7,000 meters (10,000 - 23,000 feet)
   • Cirro-cumulus
   • Alto-cumulus
   • Alto-stratus - These clouds are usually small masses, created by a combination of warm air near the ground and cooler air high in the atmosphere.
3. Below 2,000 meters (7,000 feet)
   • Strato-cumulus
   • Nimbus types
4. Diurnal ascending currents
   • Cumulus - Cumulus clouds form when the warm ground heats air and forms rising air currents. If the air rises too fast, however, the cumulus cloud may become a thunder-head or cumulo-numbus cloud.
   • Cumulo-nimbus
5. High fogs below 1,000 meters (3,000 feet)
   • Stratus - Meaning “layer” or “sheet,” these are flat, spread-out clouds.

[ back to graphics version ]

Forces of Nature: ThinkQuest 2000 (Team #C003603)

http://library.thinkquest.org/C003603/english/fogandmist/clouds.shtml