S'COOL: Cumulus Clouds
Fair Weather Cumulus
This is a fair weather cumulus scene over Pleasant Lake in New Hampshire. It is typical of summertime in the northern United States. Note that the cloud base is relatively high, as indicated by the fact that the clouds are higher than Mount Kearsarge (elev. 996 m; 753 m above the lake). Photo by Lin Chambers, July 2003.
Forming or Dissipating Cumulus
This is an example of a cumulus cloud as it is just beginning to form, or as it has mostly evaporated (a time sequence would be necessary to figure out which one). Be careful not to misclassify such wispy, isolated cumulus as some other cloud type. Look for other clues like other clouds that might be in the same layer, direction and speed of movement with the wind, etc. Photo by Lin Chambers in southeastern Virginia.
Cumulus over the Rocky Mountains
These cumulus clouds are a good example of the sort of definite shape that is typical of these clouds. Children (of all ages!) can look for familiar shapes in them. Note that, even though these clouds are above the Rocky Mountains, they are still classified as low level clouds because they are not very far above the local ground surface. Photo by Jeff Caplan, NASA photographer, during a flight testing experiment in the Rocky Mountains, August, 2001.
Cloud type is cumulus congestus: these are clouds that are more strongly developed than fair weather cumulus and may become thunderstorms later in the day if the atmosphere is sufficiently unstable. Photo taken with a Canon SLR from an aircraft by Dr. Bruce Wielicki, CERES Principal Investigator, in the late 1970s.
These are much more modest cumulus clouds, but cumulus clouds nonetheless. This photo was taken by Mandy Khaiyer form Pennsylvania State University, an area of low mountains. Looking at the regular structure of cloudiness, it is likely that these clouds are formed in waves of air moving up and down off the nearby mountains. Clouds form where the air moves up and cools to the point of water condensation. Such clouds do not show the vertical development typical of convective cumulus as above.
This is a beautiful example of trade cumulus (i.e., cumulus associated with the tradewinds) in the Tropics. Note how the clouds in the far field seem very defined, while the nearby cloud (top of photo) appears much more diffuse. This is simply a matter of distance and perspective. All these clouds are in the same low layer of cumulus. Photo taken by Doug Stoddard, March 7, 2002 on the north coast of Puerto Rico, looking towards the east.