File:Open- and Closed-Cell Clouds over the Pacific Ocean (MODIS).jpg

English: On June 6, 2023, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired a true-color image of a large swath of beautifully patterned marine stratocumulus clouds over the Pacific Ocean.

Marine stratocumulus clouds frequently form over water, especially off the western coast of both North and South America. They usually form at low altitudes (below 6,000 feet) and cover roughly 20 percent of the low-latitude oceans, or 6.5 percent of the Earth’s surface. There are two primary forms of marine stratocumulus cloud—open- and closed-cell—and both types are seen in this image. Both forms are built on honeycomb- shaped “cells”. Open-celled clouds look like empty compartments, while the structure of closed-cell clouds appears to be stuffed with fluffy white cloud.

A bank of close-cell stratocumulus cloud can act like a large blanket over the Earth, covering nearly 100 percent of the underlying land surface, and yet reflect a large portion of solar radiation. This can create a cooling effect on the Earth under the clouds. On the other hand, a bank of the more loosely-formed open-cell clouds block very little solar radiation. Open-cell clouds have been associated with the development of precipitation, with pockets of open-cell clouds opening as rain begins to fall. A deck of closed-cell clouds produces little or no drizzle.