Bright white patches in the image represent the relatively cold tops of high clouds. Clouds occur where atmospheric motions are upward. Medium gray regions depict mainly water vapor. These regions would probably appear clear on visible and ordinary infrared satellite images. Streaks and curls of gray highlight flows of middle atmospheric water vapor transported by large-scale air motions.
Dark areas are relatively dry middle atmosphere regions where air is sinking.
Midlatitude swirls are storm systems that transport humid warm air poleward to be replaced by colder and drier polar air moving equatorward. The bright white cloud blotches forming an irregular band roughly along the equator mark areas where huge quantities of water vapor enter the atmosphere from underlying warm ocean surfaces. Some of these are source regions of water vapor that flow in broad gray plumes to higher latitudes. These are regions of sinking air which, in combination with the grayer storm swirls in higher latitudes, are evidence of the vertical motions of air that occur in weather systems. B. WES Paradigm Utilizing a planetary-scale Earth system perspective, WES explores the global water cycle in which water and energy continually flow among the atmosphere, lithosphere, hydrosphere, and biosphere.