It took the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite a full five minutes to fly over this expansive cloud pattern on April 29, 2009. The sprawling “S”-shaped swirl is actually two cyclones that seem to be feeding on each other. Polar cyclones often form as a result of low-pressure systems over the ocean, and usually bring winds and heavy snow.
MODIS acquired this photo-like image over the cold waters of the South Atlantic Ocean, where winter is approaching. The image has been rotated, so that north is toward the left. The spot of green in the upper left corner of the image is coastal water off the southern tip of Africa. A north-up oriented image is available in a variety of resolutions from the MODIS Rapid Response System
The gracefully swirling clouds that sweep over hundreds of kilometers in this photo-like image are beautiful, but they were likely bringing heavy snow and strong winds to ships in the South Atlantic Ocean on April 29, 2009.
The waters off of southwestern Africa are some of the most biologically productive in the world. They also provide a compelling backdrop for exploring how satellite sensors can reveal important details of the ocean.