The shape and size of cellular patterns within marine stratocumulus cloud layerscan change dramatically with the prevailing meteorological conditions. Theseviews from the Multi-angle Imaging SpectroRadiometer (MISR) provide an example of verylarge scale closed cells, and can be contrasted with the small cells describedin an earlier image release. As described in that release, cellular structuresare associated with the sinking of air that is strongly cooled at the level ofthe cloud-tops. This type of scene is fairly typical of mid-latitude oceanicclouds unperturbed by cyclonic or frontal activity.
When the cell centers are cloudy and the main sinking motion is concentratedat cell boundaries, the cells are referred to as “closed.” The cell diameters inthis image range from 40 to 100 kilometers (about twice the average size ofclosed cells in general) and show an increased brightness at the cell centers,giving them a mogul-like appearance. Because the cloud-top heights do not varysubstantially across the cells, the distinctive appearance is more likely due toan increased concentration of cloud droplets at their centers.
The lefthand panel shows a part of the swath captured by MISR’s nadir(vertical-viewing) camera on November 25, 2001, and isdisplayed at a resolution of 1.1 kilometers per pixel (in the full-size image). The righthand panel highlights part of this scene at a resolution of 275 meters, and is centered atapproximately 49.2 degrees south latitude and 179.9 degrees east longitude,covering an area of about 233 kilometers x 240 kilometers. The images utilizedata from blocks 123 to 135 within World Reference System 2, path 68.
References & Resources
Image courtesy NASA/GSFC/LaRC/JPL, MISR Team
