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| The rising Near Space craft captures a spectacular variety of clouds at many altitudes (looking out of the cockpit window, down obliquely). This rare photo appears to show every type of cloud, including fog, rain, contrails, and other types along with their variations! |
The technique of determining altitude based on the type of cloud is only a general rule and can vary based on the location, season, local variants such as pressure, temperature and humidity, and extent of the cloud.
Based on studies and information gathered from the Big Brain's Near Space Program and data sources, the following information about cloud altitude based on the cloud type is determined. Note that some clouds exist in more than one strata level.
Generally the altitude method with clouds involves knowing your Earth position, details gained from observing the type of cloud, identifying the cloud's structure (it could exist in one strata or several stratas), and looking up the cloud on the altitude guide provided below. We will use three groups of low, medium and high altitudes. This is based on the temperate zone of the Earth. If basing on the tropics, high is 5-14 km, medium is 2-7 km, and low is 0-2 km.
LOW ALTITUDE CLOUDS
0-2KM TEMPERATE ZONE
0-2KM TROPICS ZONE
Stratus, Stratocumulus, Cumulus*, Towering Cumulus**, Cumulonimbus*, Towering Cumulonimbus**, Nimbostratus*, Fog
* Can extend into medium level
** Can extend high level
MEDIUM ALTITUDE CLOUDS
2-4 KM TEMPERATE ZONE
2-7 KM TROPICS ZONE
Altostratus, Altocumulus, Nimbostratus*
* Can exist in low level
HIGH ALTITUDE CLOUDS
3-8 KM TEMPERATE ZONE
5-14 KM TROPICS ZONE
Cirrus, Cirrocumulus, Cirrostratus, Towering Cumulus*, Towering Cumulonimbus*, Contrails
* Can exist in low level
RAIN CLOUD TIPS
If it rained recently or is about to rain, you are most likely dealing with a low level stratus cloud. While it is possible for rain to fall from mid-level clouds, it is quite rare. If it is raining during your observation, you have nimbostratus (or cumulonimbus - but the difference should be obvious! The latter is a thunderstorm). The terms nimbo/nimbus are from a Latin word for rain.
LOW LEVEL TIPS
If a Stratus cloud is so thick you can't even figure out where the sun is, most likely it is a low level stratus. The visual opacity of such a cloud is opaque.
MEDIUM LEVEL TIPS
If you can see the sun but it looks diffused (like looking through a glass bottle), most likely you have Altostratus. The visual opacity would be translucent.
HIGH LEVEL TIPS
High-level Cirrostratus will generally be thin enough that the sun is still quite distinct. If the Cirrostratus is not between you and the sun, you may be able to distinguish Cirrostratus as being so thin that parts of the cloud appear bluish (that is, you are seeing through to blue sky). The visual opacity is transparent.
LINKS
Cloud Type Determinations
http://wvscience.org/clouds/Cloud_Key.pdf
