Open cloud cells off Chile
Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC
This lacy swirl of clouds were captured off the coast of Chile in the Pacific Ocean by NASA's Terra satellite on July 19, 2002. The dark swirl in the center of this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image is made up of open-cell cumulus cloud patterns. These cells, or parcels of air, often occur in roughly hexagonal arrays in a layer of fluid (the atmosphere often behaves like a fluid) that begins to "boil," or convect, due to heating at the base or cooling at the top of the layer.
In "open" cells air is falling in the center, and rising around the edges, so clouds appear in around the edges, but evaporate in the center. This creates a lacy, hollow-looking pattern like the clouds in the top center.