This article refers to meteorology. For the airborne base of the TV series Captain Scarlet and the Mysterons, see Cloudbase. The cloud base (or the base of the cloud) is the lowest altitude of the visible portion of the cloud. It is traditionally expressed either in m or feet above mean sea level (or planetary surface), or as the corresponding pre...
For a given cloud or cloud layer, it is the lowest level in the atmosphere where cloud particles are visible.
The height at the bottom of a towering cloud.
For a given cloud or cloud layer, it is the level in the atmosphere cloud particles (droplets or ice crystals) become visible.
the apparent lower surface of a cloud or cloud layer.