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.