This video was produced for Earth Science Week 2009 (Oct 9-16th). It was one of six videos. The rest of the videos produced by our team can be found here: http://climate.nasa.gov/esw/videoseries/
Water is all around us, and its importance to nearly every natural process on earth cannot be underestimated. It is vital to life, but it is also tightly coupled to climate, helping to carry heat from the tropics to higher latitudes. Changes to the water cycle affect climate and vice versa. The water cycle is the movement of water around the Earth in all its forms. Imagine the path a molecule of water might take after it evaporates from the salty ocean. It might condense and return to the ocean as rainfall, or it might move through the atmosphere as water vapor and fall onto the land surface as freshwater rain or snow. Snow may become part of an ice cap or glacier, where the water molecule could remain for centuries, or it might soon melt and enter the soil or a stream. Rain wets the soil, becoming available for plants to use. The water molecule may drain into an aquifer, where it could remain for many years before feeding into a stream. Streams flow into lakes and rivers, but along the way the water molecule might be captured for use industry, agriculture, or drinking and other domestic needs. Ultimately, the water molecule will return to the ocean where the journey begins anew. This video explains what the water cycle is and how important it is to life on earth.
