The summer skies over the Pacific Ocean off the coast of Baja California were filled with a spectacular pattern of open-cell and closed-cell clouds on in June 22, 2011, when the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite passed over the region and captured this true-color image.
In this image, clouds appear to be formed in cell-shaped structures that resemble compartments in a honeycomb. The majority of the cells are fully filled with puffy white clouds, giving the cloud deck a textured appearance from space. These clouds, with full cells, are called “closed-cell clouds”. In contrast, in some areas only the lacy structure can be seen, while the center of the cells appears to be empty. These are open-cell clouds.
In closed-cell clouds, warm air rises in the center cell and sinks around the edges. Rising air combined with moisture over the ocean is favorable for the formation of clouds, and so the centers of these cells fill with cloud. Meanwhile, at the edge of these cells, the air sinks and the clouds dissipate. In contrast, in open-cell clouds, the air sinks in the center of the cell and rises along the edges, creating the opposite cloud pattern – open centers and white cloudy edges.
The closed-cell clouds appear to have a greater volume, and it would be reasonable to think that the chance of precipitation is greater with a larger volume of cloud. However, it is the open-cell clouds that are actually associated with the development of precipitation. Uninterrupted decks of closed-cell stratocumulus clouds produce little or no rain. Pockets of open cells appear as drizzle begins to fall.