1. Air masses get their characteristics based on
where
they
form

2. The abbreviations used to classify air masses
use the following letters: c, m, T, P, and A.
For each letter, describe its property:
Word
Means c m T P A
continental
dry
maritime
moist
Tropical
warm
Polar
cold
Arctic
very cold

3. What would their characteristics be?mT cP
warm and moist
cold and dry

6. What type of air mass
would form over each
area? Please label. cA mP mP cP cT mT mT mT

7. World Air Mass
Source Regions

10. Animation #1

11. cP air mass
dry, cool air
High Pressure Area
mT air mass
warm, moist air
Low Pressure Center

12. cP air mass
dry, cool air
High Pressure Area
mT air mass
warm, moist air
Low Pressure Center

13. cP air mass
dry, cool air
High Pressure Area
mT air mass
warm, moist air
Low Pressure Center

14. cP air mass
dry, cool air
High Pressure Area
mT air mass
warm, moist air
Low Pressure Center

15. cP air mass
dry, cool air
High Pressure Area
mT air mass
warm, moist air
Low Pressure Center

16. Air Masses Facts:
Air mass is a region of air with similar properties in the atmosphere
Air mass typically move from the west to the east in the Northern Hemisphere under the influence of the prevailing westerlies.
Example: Hot, dry air from the continental tropical air mass will bring hot, dry weather to Texas when it moves in from Arizona.
Masses of air that stay in place for some length of time take on the characteristics of temperature and humidity from the surface of the earth over which the air stands.
Masses of air that originate over the ocean tend to be moist
There are four major types of air masses that affect the weather in the United States:
Maritime Tropical
Maritime Polar
Continental Tropical
Continental Polar

17. Characteristics Name Characteristics Maritime Tropical
Forms near the equator.
Warm, moist air
Summer- very hot, humid weather
Winter - rain or snow
Maritime Polar
Forms over the Pacific Ocean in both the winter and the summer.
Summer – cooler temperatures to the eastern states and fog to California and other western states.
Winter- Heavy snow and very cold temperatures
Continental Tropical
Forms over land in Mexico.
Brings dry, hot air to the southwestern states.
Continental Polar
Forms over land in northern Canada.
Winter- very cold temperatures in the United States

19. High and Low Pressure Systems
High Pressure Areas (H) – air tends to sink, winds blow outward from the center, turning clockwise. High pressure area usually brings clear skies, dry weather, and gentle winds.
Low Pressure Areas (L) – the air tends to rise, and winds spiral in toward the center in a counterclockwise direction. The low pressure areas usually brings cloudy, wet weather, often with strong, gusty winds.

20. High and Low Pressure Systems
Areas of high pressure can be caused when cool air is sinking and pressing on the ground. When warm air rises, however, it causes a region of low pressure.
Regions of sinking air are called highs, high pressure regions, or anticyclones. Clear skies and fair, dry weather usually occur in these regions.
Regions of rising air are called lows, low pressure regions, depressions, or cyclones. Clouds, rain, and strong winds often occur in these regions.