Air Masses, Geography and Weather.

1. Air Masses, Geography and Weather. Note-taking Required (Use the Cornell Method)

2. Analysis of weather data shows: Regions near oceans tend to have moderate temperatures. Regions distant from oceans tend to have extreme temperatures. Regions near oceans tend to have high annual rainfall. Regions distant from oceans tend to have low annual rainfall.

3. What accounts for these general climate trends? The formation and movements of air masses. The influence of topography on the movement and characteristics of air masses. Seasonal changes resulting from the effect of latitude on the duration and angle of sunlight.

4. Vocabulary to know… Air Mass - a region of the atmosphere that has specific temperature and moisture characteristics Maritime (or marine) air mass - An air mass that forms over oceans and is therefore a wet air mass Continental air mass - An air mass that forms over land and is therefore a dry air mass

5. More important terms… Tropical air mass - An air mass that forms at low latitude, and is therefore a warm air mass Polar air mass - An air mass that forms at high latitude, and is therefore a cold air mass. We combine pairs of terms to describe any given air mass based on temperature and moisture characteristics.

6. Four kinds of air masses… Maritime tropical air mass - A warm and wet air mass, forming over low latitude oceans. Maritime polar air mass - A cold and wet air mass, forming over high latitude oceans. Continental tropical air mass - A warm and dry air mass, forming over low latitude land. Continental polar air mass - A cold and dry air mass, forming over high latitude land.

7. Other facts about air masses… Maritime air masses do not tend to get as warm or cold as continental air masses. Why?

10. Where do air masses form, and what factors separate and protect some regions from the influence of the oceans?

11. North America is generally affected by six different air masses…

12. Local weather conditions are a result of the air mass that is affecting our area.

13. Local weather conditions are a result of the air mass that is affecting our area.

14. Local weather conditions are a result of the air mass that is affecting our area.

15. Local weather conditions are a result of the air mass that is affecting our area.

16. Storms occur when air masses interact with each other. A “Weather Front” occurs when one air mass collides with another air mass. A “Warm Front” occurs when a warm air mass collides with and replaces a cold air mass. A “Cold Front’ occurs when a cold air mass collides with and replaces a warm air mass.

17. A typical warm front occurs when a maritime tropical air mass collides with a continental polar air mass.

18. Warm fronts cause clouds and steady rain.

19. A typical cold front occurs when a maritime polar air mass collides with a continental tropical air mass.

20. Cold fronts cause clouds and heavy, showery rain.

21. Why does Western Washington get more rain than Eastern Washington?