Earth Science Name ____________________________ Date __________ Per. ____

Study Guide: Water Cycle & Humidity

1. Explain the difference between Specific Humidity and Relative Humidity. ____Specific humidity refers to the

actual amount of water vapor in the air, while Relative humidity refers to how close the air is to reaching its

maximum capacity of water vapor (expressed as a percentage).

2. What are “condensation nuclei” and why are they important? ___Tiny specks of dust around which water

droplets form. They are important because water vapor cannot condense into liquid water without a small solid

particle to attach onto.___

3. What are some features on earth that make up the “Hydrosphere”? ___Rivers, lakes, ponds, oceans, and

streams____________________________

4. Describe “Transpiration”: When plants release water vapor directly into the

atmosphere.___________________Where on earth do you think the most transpiration is occurring?

______Anywhere where there is heavy vegetation (Rainforests)__________________

5. What two water cycle processes must liquid water on the ground undergo before it can be formed into

clouds? ______Evaporation and then Condensation________

6. Sometimes, when you wake up in the morning, there are drops of water on the ground and on your

windows, but it did not rain. What happened overnight to cause this? ___________The temperature

dropped to the Dew Point and the water vapor in the air condensed into liquid water.

7. Where is the heat stored that provides the energy that drives our weather and climate? _____In the

Oceans_________

8. What does it mean when the air is “saturated”? ____It has reached 100% capacity and cannot hold any more

water vapor._____

9. Explain the difference between “weather” and “climate”. Weather is the state of the atmosphere at a given

place and time, and changes daily. Climate is an area’s long-term weather patterns (usually in averages).

10. List all the factors that determine an area’s climate: ____Latitude, Vegetation, Elevation, Prevailing Winds,

Nearby Water, Ocean Currents, Topography________________________________________

11. What is the temperature at which condensation begins referred to as? ___Dew Point__________

12. Which of the volumes of air below would be able to hold the most water vapor? Explain. ______D. It has

the highest temperature, and warmer air can hold more moisture than cold air.

13. What is the name of the instrument that is used to measure humidity? ____Psychrometer_____

14. As the temperature of the air cools and gets closer to its Dew Point, what happens to the Relative

Humidity? _It increases. Cooler air cannot hold as much moisture as warm air, so as the temperature decreases,

the percentage of water vapor in the air increases (even though the amount of water vapor stays the same).

15. On a sunny day during the winter, a large snow-bank will slowly decrease in size without the snow melting

first. This is because the snow is changing directly from a solid to a gas. What is this process called?

______Sublimation__________

3⁰F 15⁰F 31⁰F 62⁰F

16. Write the name of the process that describes the change in the state of water below:

17. Use the word bank below to fill in the blanks in the Water Cycle diagram:

Accumulation

Surface Runoff

Groundwater (Sub-surface Runoff)

Condensation

Condensation

Precipitation

Evaporation

Transpiration

Label each diagram below with the correct type of Precipitation (Sleet, Rain, Freezing Rain, and Snow):

Water

Vapor

Melting Evaporation

Condensation Freezing

Condensation

Transpiration

Surface Run-Off

Precipitation

Condensation

Evaporation

Accumulation

Groundwater

Rain Snow Sleet Freezing Rain

Using the table above, answer the following questions:

18. Dry-Bulb Temp. = 22⁰C, Wet-Bulb Temp. = 20⁰C.

What is the Dew Point temperature? ___19°C____

19. Dry-Bulb Temp. = -2⁰C, Wet-Bulb Temp. = -6⁰C.

What is the Dew Point temperature? ___-20°C ____

20. Dry-Bulb Temp. = 12⁰C, Wet-Bulb Temp. = 12⁰C.

What is the Dew Point temperature? ___12°C _____

21. Difference between Temps = 8⁰C, Dew Point = 13⁰C.

What is the Dry-Bulb temperature? ____26°C ___

Using the table above, answer the following questions:

22. Dry-Bulb Temp. = 22⁰C, Wet-Bulb Temp. = 20⁰C.

What is the Relative Humidity? ____83% ____

23. Dry-Bulb Temp. = -4⁰C, Wet-Bulb Temp. = -6⁰C.

What is the Relative Humidity? ____54% ___

24. Dry-Bulb Temp. = 12⁰C, Wet-Bulb Temp. = 2⁰C.

What is the Relative Humidity? ___2% ___

25. Difference between Temps = 8⁰C, Relative Humidity = 36%.

What is the Dry-Bulb temperature? ___20°C ___

26. Air Temp. = 30⁰C, Dew Point = 22⁰C. What is the height of the base of the clouds? ___1 km___

27. Air Temp. = 40⁰C, Dew Point = 12⁰C. What is the height of the base of the clouds? __3.5 km ___

28. Air Temp. = 0⁰C, Dew Point = -8⁰C. What is the height of the base of the clouds? __1 km ____

29. Cloud Base Height = 2 km, Dew Point = 14⁰C. What is the air temperature? __30°C __