Water Cycle and the Atmosphere

1. Water Cycle and the Atmosphere

2. Where is water on Earth? • Reservoirs- protected artificial or natural lakes • Groundwater- water that collects underground

3. Water Cycle • The continuous movement of water from the atmosphere to the earth’s surface and back to the atmosphere again. • Aka: hydrologic cycle • Parts of the Water Cycle • Evaporation • Transpiration • Runoff • Ground Water • Condensation • Precipitation

5. Parts of the Water Cycle • Evaporation: liquid water changes into water vapor • Transpiration: plants give off water vapor into the atmosphere • Runoff: flows over land into rivers • Ground Water: water that soaks deep into the soil and rock underground • Condensation: water vapor cools into tiny liquid water droplets (clouds) • Precipitation : water falls from clouds to the earth’s surface (rain, snow, sleet, and hail) • Aquifer: Underground area of sediment and rocks that hold groundwater

7. What's in Earth's atmosphere? • This protective layer exists around Earth because our planet has just the right balance of size and distance from the sun.

8. The Atmosphere • Earth’s atmosphere is a layer of gases surrounding the planet, protecting and sustaining life. • It insulates us so that we don’t freeze at night. • Its ozone layer protects us from the sun’s ultraviolet rays.

9. Atmospheric pressure • Atmospheric pressure is a measurement of the force of air molecules in the atmosphere at a given altitude. • The pressure of the atmosphere changes as you rise above sea level.

10. Pressure changes with altitude

11. Parts of an Aneroid Barometer

12. Layers of the Atmosphere • Four Layers • Thermosphere • Mesosphere • Stratosphere • Troposphere* • The atmosphere is divided into layers based on temperature changes. • We live in the troposphere which is 0 to 11 kilometers above Earth's surface.

13. Layers of the Atmosphere The four layers of the atmosphere include: • the troposphere, where we live; • the stratosphere, which contains the ozone layer; • the mesosphere, where meteors burn; • and the thermosphere,where satellites orbit Earth.

14. Energy in the Atmosphere • Our sun converts 5 million tons of its own mass into energy every second. • This process involves nuclear fusion. • Even though Earth intercepts only a tiny fraction of the radiation broadcast by the sun into space, this radiation provides most of Earth’s thermal energy.

17. Greenhouse effect • There are molecules in the atmosphere that act like the pebbles in the bucket. • They make it take longer for the infrared radiation to escape back into space compared to bucket with no pebbles.

18. Greenhouse effect • Adding greenhouse gases to the atmosphere is like adding more pebbles to the bucket. • It takes longer for radiation to escape from the atmosphere, so Earth’s average temperature rises.