1. Chapter 8 cover

2. air masses An air mass is a large body of air that has similar temperature and moisture properties throughout. The best source regions for air masses are large flat areas where air can be stagnant long enough to take on the characteristics of the surface below.

3. Figure 8.1

4. temperatureP-PolarA-ArcticT-Tropical humiditym-Maritime-wetc-Continental-dry classifying air masses

5. air masses

6. North American air masses

7. cP Continental Polar Air Masses cold temperatures and little moisture

8. cP a map of surface observations and the leading edge of a large arctic air mass blanketing much of the United States has been highlighted by the blue line. The center of this air mass is a high pressure center located in northern Montana (indicated by the blue "H") Continental Polar Air

9. mT Maritime Tropical Air Masses warm temperatures and rich in moisture

10. mT Maritime Tropical Air a map of surface observations and the leading edge of a tropical air mass surging northward into the Ohio Valley has been highlighted in red. Southerly winds behind the boundary signify the continued northward transport of warm moist air

11. k-coldw-warm air mass modification

12. cP-w

14. fronts

15. cold front

16. Figure 8.2

17. Figure 8.3

18. fronts

19. warm front

20. Figure 8.4

21. fronts

24. occluded fronts

25. mid-latitude cyclone

26. formation of an occlusion

27. mature cyclone

28. partial occlusion

29. occlusion

30. life of a midlatitiude cyclone

31. Figure 8.8

32. Figure 8.9

33. Figure 8A

34. Figure 8.10

35. Figure 8.7