Animation of the water cycle on Earth. These are the processes by which water circulates between the oceans, the atmosphere and the land. The animation starts with the Sun, whose energy drives the cycle. Evaporation from the sea causes clouds to condense in the atmosphere. These clouds grow as more water evaporates, and can drift over land. Where they meet high ground, the air rises and the water condenses and falls as rain, and snow on higher ground. The water flows down the mountains in narrow, steep streams. The ground cuts away to show the infiltration of the rock by the water, which runs downhill both above and below ground. At lower levels, porous rock and soil absorbs water, giving rise to a water table (blue). Where this meets the surface, lakes can form. Water is essential for life, and wet areas support forests and other vegetation. Evaporation from the ground returns some water to the air, and transpiration from plants contributes also. The run-off of water continues until the rivers and the groundwater flow into the sea. The closing stages of the animation show the entire cycle.