Water Cycle

The continuous movement of water between the ocean, atmosphere and land, driven by solar heating: water evaporates from ocean and land surfaces, is transpired by plants into the atmosphere, condenses into clouds, falls as precipitation, and returns to the ocean through rivers and groundwater flow to begin again. Forested biomes participate in this cycle directly rather than merely receiving its output; the Amazon rainforest's trees transpire enough water vapor to generate a substantial share of the region's own rainfall, a self-reinforcing local loop researchers call flying rivers, and large-scale deforestation measurably reduces downwind precipitation as a result. The ocean, covering most of the marine biome's area, is both the water cycle's largest reservoir and the source of most of the water vapor that eventually falls as rain over land.