1. Chapter 2 UNDERSTANDING WEATHER
WEATHER AND CLIMATE
Chapter 2
UNDERSTANDING WEATHER

2. Section 1A
Water in the Air

3. the condition of the atmosphere at a particular time and place
weather

4. the continuous movement of water from water sources into the air, onto land, into and over ground, and back to the water sources
water cycle

5. the change of state from a liquid to a vapor
evaporation

6. the process by which plants release water vapor into the air through their leaves
transpiration

7. the change of state from a gas to a liquid
condensation

8. solid or liquid water that falls from the air to the Earth
precipitation

9. Cold Weather Precipitation

10. water, usually from precipitation, that flows across land and collects in rivers, streams, and eventually the ocean
runoff

11. the amount of water vapor or moisture in the air
humidity

12. As water evaporates, the humidity of the air _________.
increases

13. Humidity can cause a _________
day.
bad hair

14. As temperature decreases, the air’s ability to hold moisture __________.

15. Warmer air can hold _______ water vapor than cooler air.
more

16. the amount of moisture the air contains compared with the maximum amount it can hold at a particular temperature
relative humidity
Actual Amount Compared to Maximum Amount
Relative Humidity of 5/10 =50%

17. Calculate Relative Humidity:
The air actually holds 8 grams of water vapor at a temperature that could hold 32 grams of water vapor
The air could hold 50 grams of water vapor but actually holds 40
25%
80%
Hint: Divide the amount in the air by the amount it can hold. Then multiply by 100.

18. instrument used to measure wind speed
anemometer

19. an instrument used to measure relative humidity
psychrometer

20. Using the following slide, determine the relative humidity when:
the dry-bulb reading is 16˚C with a wet-bulb difference of 7

21. Relative Humidity (in Percentage)
Dry-Bulb Reading ˚C
Difference Between Wet-Bulb Reading
and Dry-Bulb Reading 1 2 3 4 5 6 7 8 81 64 46 29 13 84 68 52 37 22 85 71 57 43 16 86 73 60 48 35 24 11 87 75 63 51 40 19 10 88 77 66 55 44 34 15 12 89 78 58 39 21 14 90 79 70 42 26 54 38 30 18 91 82 65 49 41 20 83 74 59

22. Using the following slide, determine the relative humidity when:
the dry-bulb reading is 4˚C and the wet-bulb reading is 10˚C.
HINT: 1st Find the difference!
10 – 4 = 6

23. Relative Humidity (in Percentage)
Dry-Bulb Reading ˚C
Difference Between Wet-Bulb Reading
and Dry-Bulb Reading 1 2 3 4 5 6 7 8 81 64 46 29 13 84 68 52 37 22 85 71 57 43 16 86 73 60 48 35 24 11 87 75 63 51 40 19 10 88 77 66 55 44 34 15 12 89 78 58 39 21 14 90 79 70 42 26 54 38 30 18 91 82 65 49 41 20 83 74 59

24. When air holds all the water it can hold at a given temperature, it is said to be _________.
saturated

25. Saturated air has a relative humidity of ____%.
100

26. If the amount of water vapor in the air stays the same, the relative humidity __________ as the temperature rises.
decreases

27. Before condensation can occur, the air must be ________ and cooled.
saturated

28. the temperature to which air must cool to be completely saturated
dew point

29. Before it can condense, water vapor must have a _______ on which it can condense.
surface

30. Fun and Games Bill Nye the Science Guy on “The Water Cycle” Part 1
Magic School Bus “Wet All Over”
Water Cycle Animation

31. Fun and Games Brain POP Video, Activities, and Quiz on Humidity
User Name: tabernaclesd_2
Password: brainpop
Water Cycle
Vocabulary Games