Water Cycle

a description of how water is not only always changing forms (between liquid [rain], solid [ice], and gas [vapor]) but also moving on, above, and in the Earth this movement of water includes living things as every living thing needs water

Open vs. Closed System Open System –a system where materials involved in the system move into and/or out of the system freely Ex: an open pot on a hot stove top Closed System –a system where materials involved in the system are unable to leave the system Ex: a covered pot on a hot stove top

Earth Systems different systems involving the matter (materials) of the earth each of these systems can serve as an area where water is stored until it moves into another system in the water cycle Hydrosphere Atmosphere Biosphere Lithosphere

Earth Systems

1. Hydrosphere water on the surface of the earth can be stored in: –Oceans –Freshwater (Rivers and Lakes) –Ice and snow (Glaciers)

2. Atmosphere gases that surround the earth can store water in: –water vapor in the air –clouds

3. Biosphere earth’s living organisms can store water in: –the tissues of living things

4. Lithosphere earth’s rocks and soil can store water in –groundwater

Earth Systems

Water Transition Processes water has many ways of moving between earth’s systems there is no specific order to this movement 1.Biological Uptake 2.Condensation 3.Evaporation 4.Evapotranspiration 5.Infiltration 6.Precipitation 7.Runoff 8.Seepage 9.Sublimation

1. Biological Uptake water gets used by all types of living things

2. Condensation water vapor in the air cools down it becomes liquid water again as clouds

3. Evaporation liquid water on Earth (in oceans, lakes, etc.) turning into water vapor that rises into the sky –this process is driven by heat from the sun

4. Evapotranspiration plants lose water which is absorbed into the atmosphere much like evaporation –if the plants loses too much water to this process and doesn’t replace the lost water with water from their roots, the plant will wilt

5. Infiltration surface liquid water percolates (passes) through the soil into the ground –can remain here for extended periods of time in an aquifer or make its way to a river, lake, ocean, or spring Aquifer – rock that contains water

Artesian Wells

6. Precipitation water falls from the sky in the form of rain, snow, hail, or sleet

7. Runoff water on the surface joining a larger body of water includes liquid water on the surface and the melting of ice and/or snow

8. Seepage groundwater from the lithosphere returning to the surface also sometimes called discharge

Artesian Wells

9. Sublimation a solid transforming directly into a gas without first becoming a liquid –the most common example of sublimation is dry ice (solid carbon dioxide) which sublimes at normal air temperature –under certain conditions, snow and ice can sublime into water vapor the opposite process is called desublimation or deposition –can see this occur on frost on cars’ windshields

Summary Is the water cycle an open system or a closed system on Earth?