The Earth acts as a giant engine that uses solar power to move air in the atmosphere and water in the oceans. This engine drives the water cycle, the movement of water from the oceans to the atmosphere by evaporation, from the atmosphere to the land by precipitation, and from the land back to the oceans by rivers and streams. The water cycle, the subject of a multi-part series of stories beginning today, provides nearly all the fresh water consumed by plants and animals. The cycle begins when the top one meter of the ocean absorbs sunlight. Heat from the sunlight is then dispersed within the top 100 meters of the ocean by waves. These 100 meters of ocean can absorb a lot of heat without much change in temperature. In fact, the ocean cools off very little at night. The land, however, is heated to less than one meter deep. Land temperature changes rapidly, even from night to day. The animations below show multiple views of the solar heating of the oceans, a dynamic picture of this vital first stage of water's cyclical journey from sea to air to land, and back again.

View Part 2: Steaming the Air