Atmosphere

The Earth is bathed in energy from the Sun. The oceans, land, and atmosphere absorb and are heated by this energy. The heat absorbed by the oceans and transported by its currents is constantly released into the atmosphere. Heat and moisture from the oceans drive atmospheric circulation and weather patterns. Moisture in the atmosphere forms clouds which cover an average of 40% of the Earth at any given time. Clouds are carried through the atmosphere by the wind. The patterns in cloud motion in this time-lapse sequence show how Earth's winds move in bands or zones which define regional wind directions.

The movement of moisture or water vapor in the atmosphere is important in determining the weather. In the swirling motion of atmospheric water vapor, hurricanes can be seen. During the summer of 1995, a series of hurricanes formed off the coast of Africa -- Allison, Erin, Felix, Humberto, Iris, Luis, Marilyn, Noel, Opal, Roxanne, and Tanya -- then moved west across the Atlantic to the Caribbean and East coast of the United States. The white and light blue areas contain the most water vapor, while the dark areas are the driest.
The small bright areas are storms and hurricanes. The big spirals show large-scale circulation patterns in the Earth's atmosphere.