1. Water Cycle

2. Evaporation
Liquid water gains heat and turns into water vapor.

3. Condensation
Water vapor loses heat and turns into liquid water.

4. Precipitation
Water falling from the sky.

5. Transpiration
The process of emitting water vapor through the leaves of plants .

6. Weather Factor #4: Water
Water in the atmosphere vapor clouds

7. Humidity Measure of the amount of water vapor in the air.
Amount depends on the air temperature.
Warm air can hold more water vapor.

8. Relative Humidity
Percent of water vapor that is actually in the air compared to the maximum amount it can hold at a particular temperature.

9. Tool to measure relative humidity
Sling Psychrometer

10. Relative Humidity
Example at 10 degrees Celsius 1 cubic meter of air can hold 8 grams of water vapor; if there were 8g of vapor in the air then the relative humidity would be 100%. What would the relative humidity be if the same cubic meter of air had 4 g of water vapor? 50 %

11. Relative humidity is 25%, how many grams of water? 2 g
at 10 degrees Celsius 1 cubic meter of air can hold 8 grams of water vapor; if there were 8g of vapor in the air then the relative humidity would be 100%.
Relative humidity is 25%, how many grams of water?
2 g

12. What happens if the temperature of the air increases?
Warm air can hold more water

13. Why might condensation occur if air is cooled enough?
The amount of water in the air would become greater than the air could hold.

14. Dew Point The temperature at which condensation begins.
Must have surface to condense on.
Dew point below 0 degrees C
Frost

15. Condensation forms clouds.
Tiny particles in the atmosphere provide surface for water vapor to condensate on.
Dust
Salt
Smoke

16. Clouds
Stratus- flat layered clouds, spread out usually cover the sky. Low level clouds.

17. Cumulus
Fluffy rounded piles of cotton. Low level clouds.

18. Cirrus
Wispy, feathery clouds. High level clouds.

19. Add-ons Alto- high Nimbo/Nimbus- rain Altostratus Altocumulus
Nimbostratus
Cumulonimbus

20. Precipitation
Rain.
Sleet- as rain falls through air that is below 0 C it freezes.
Freezing rain- rain freezes as it hits cold surface.
Snow- vapor converted directly to ice crystals.
Hail- ice pellets, updrafts push it back into the cumulonimbus cloud where it grows.

21. Cloud Seeding
Silver oxide
Dry ice