1. Air Masses and their Movements
Chapter 6.3

2. 4 Major types of air masess
There are 4 major types of air masses that influence weather in North America:
A. maritime tropical
B. maritime polar
C. continental tropical
D. continental polar

3. Air mass
A huge body of air that has similar temperature, humidity, and air pressure at any given height.

4. Tropical
Warm air masses that form in the tropics and have low air pressure.
TROPICAL

5. Polar
Cold air masses that form north of 50o north latitude and south of 50o south latitude, with high air pressure.
POLAR

6. Maritime
Air masses that form over oceans, usually very humid.

7. Continental
Air masses that form over land, usually drier than maritime air masses.

8. What are the major air masses?
Continental
tropical
Maritime
tropical
Maritime
polar
Continental
polar

9. Jet streams
Bands of high-speed winds about 10 km above Earth’s surface; generally blow from west to east.

10. I get it! Now I know that the 4 major types of air masses are…. Pg. 203
Maritime tropical
Wet/warm
2. Continental tropical Dry/warm
3. Maritime polar Wet/cold
4. Continental polar Dry/cold

11. Maritime Polar:
Cool, humid air masses form over North Atlantic often pushed out to sea by westerly winds. These can also form over the Pacific Ocean and can bring cool weather to the west coast.

12. Continental Polar
These form over Canada and Alaska, can bring bitterly cold weather with low humidity.

13. Maritime Tropical
Warm, humid air masses that form over the Gulf of Mexico and the Atlantic Ocean. Often bring thunderstorms with heavy rain or snow. If they form over the Pacific Ocean they bring hot, humid weather with summer showers.

14. Continental Tropical:
Hot, dry air masses that form mostly in the summer over the Southwest or N. Mexico. They can bring hot, dry weather to the great plains.

15. Front
The boundary where air masses meet.

16. Weather @ the Front pgs. 204-205
Clouds, many
days of precipitation
Clouds, heavy
precipitation
Clouds, many
days of precipitation
Clouds, precipitation

17. Occluded
Cut off, as in a front where a warm air mass is caught between two cooler air masses. Most complex of the different fronts

18. What are the main types of fronts?
 Warm Front
Cold Front 
Stationary
Front
Occluded 
Front

19. What weather do cyclones and anticyclones bring?
Cyclones and decreasing air pressure are associated with … clouds, wind, and precipitation.
Anticyclones are associated with … dry, clear weather.

20. Cyclone
A swirling center of low air pressure.

21. Anticyclone
High-pressure centers of dry air.

22. Air Masses and Their Movements
Cyclones and Anticyclones
Which image is a cyclone and which is an anticyclone? What is the air motion direction of each?
Cyclone
Anticyclone

23. Air Masses and Their Movements
Pg. 207
Which circles are low-pressure centers and which are high-pressure centers? L H L H

24. I get it! Now I know that… pg. 207
Cyclones cause…. clouds, wind, and precipitation
Anticyclones cause… dry, clear weather