1. Chapter 7 Water and Atmospheric Moisture

3. Water on the earth: Land and Water Hemispheres
2/3 earth’s surface areas are water body
Most land is over northern Hemisphere
Figure 7.2

4. Ocean and Freshwater Distribution
Figure 7.3

6. Unique Properties of Water
Heat properties 
Phase change
Latent heat: heat related to water phase change
Heat properties of water in nature  

7. Three States of Water
Figure 7.5

8. Phase Changes
Figure 7.7

9. Uniqueness of Ice Forms
Figure 7.6

10. Humidity
Saturation: air is holding the maximum amount vapor at the given air temperature.
Expressions of humidity  
Vapor pressure
Specific humidity
Relative humidity
Dew point
Instruments

11. Water Vapor in the Atmosphere
Figure 7.10

12. Water Vapor in the Atmosphere
Figure 7.10

13. Vapor pressure: pressure created by water vapor alone Saturation Vapor Pressure: maximum vapor pressure at a given air temperature. It increases with air temperature, more rapidly at higher air temperatures
Figure 7.12

14. Specific humidity: the amount of water (g) vapor in a kg of dry air Maximum Specific Humidity: the saturation specific humidity at a given air temperature
Figure 7.13

15. Relative Humidity: (actual vapor)/(saturation vapor); how close the atmosphere to the saturation
Figure 7.8

16. Humidity Patterns
Air temperature increases, the relative humidity decreases if there is no change in vapor amount in the air
Figure 7.11

17. Humidity Instruments: hair hygrometer; dry-and-wet bulb thermometer
Figure 7.14

18. Dew point temperature
The air temperature when air reaches saturation (when dew starts to form)

19. Clouds and Fog Cloud Formation Processes
Cloud Types and Identification  
Fog  

20. Cloud Formation Processes
Moisture droplets
Cloud-condensation nuclei

21. Moisture Droplets
Figure 7.20

22. Raindrop and Snowflake Formation
Ice crystal process: ice crystals grow and water droplets evaporate
Collision and coalescence: large droplets merges with smaller ones
Figure 7.21

23. Cloud Types and Identification
High clouds: cirrus, cirrostratus, cirrocumulus
Middle clouds: altostratus, altocumulus
Low clouds: stratus, stratocumulus, nimbostratus
Clouds with vertical development:
Cumulus
cumulonimbus
Figure 7.22

24. Cirrus
Figure 7.22

25. Cirrostratus
Figure 7.22

26. Altocumulus
Figure 7.22

27. Altostratus
Figure 7.22

28. Nimbostratus
Figure 7.22

29. Stratus
Figure 7.22

30. Cumulus
Figure 7.22

31. Cumulonimbus
Figure 7.22

32. Cumulonimbus Development
Thunderstorm cloud: with updraft and downdraft in different parts of the cloud
Figure 7.23

33. Fog: clouds with based on the ground
Advection fog
Evaporation fog
Upslope fog
Valley fog
Radiation fog

34. Advection Fog: warm and moist air moves over a cooler surface
Figure 7.24

35. Evaporation Fog: warm water evaporates into colder air above
Figure 7.25

36. Radiation Fog: radiation cooling of the land surface chills the near surface air. Condition: clear sky, calm (light wind). Most common in fall and winter
Figure 7.27