2.  The movement of water through a cycle by phase changes: liquid, gas, and solid water.  Condensation- vapor cools and becomes liquid droplets  Evaporation- liquid water changes into water vapor

3. Water Cycle (cont.)  Transpiration- plants releasing water vapor  Precipitation- rain, snow, sleet, or hail fall from clouds  Runoff- water collects on the ground and becomes rivers, streams, etc.

4. Water Cycle

5. Water on Earth  97.2% is saltwater  2.8% is freshwater

6. Our Water 75% Del Valle 25% Ground water Where is our water from? How do we use our water? 80% Parks, Gardens, Agriculture 20% Drinking

7. Water Shortage  California is a desert, we will always need to conserve and recycle water.  Growing population requires increased supply.  California will run out of water in 2020 at current rates.

8. Humidity  The amount of water vapor in the air  Air’s ability to hold moisture depends on temperature –Warmer air can hold more moisture Relative Humidity- a ratio of of how much water in air compared to the max it can contain

9.  A collection of millions of water droplets or ice crystals

10.  Puffy clouds with flat bottoms  Form from warm air rising  If they get very large that can produce thunder showers

11. Cumulus Clouds

12.  Form in layers (strata), and cover large areas of the sky blocking out the sun

13.  Thin feathery white clouds that form at high altitudes

14. Air Masses and Fronts  A large body of air that influences weather  Cold air masses- bring cold weather to U.S., form over Canada, the No. Pacific Ocean, and the No. Atlantic Ocean

15. Warm Air Mass  Develop over the Atlantic and Pacific oceans, the gulf of Mexico, and the desert region of Mexico.

16. Fronts  The boundary where two different air masses meet