Educational worksheet on air masses with a U.S. map and classification chart.

Let’s solve this step by step.

We’re learning about air masses — big bodies of air that have similar temperature and humidity (moisture) throughout. They form over large areas like oceans or continents, and they get their name from where they come from.

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Part A: True or False?

We’ll go one statement at a time.

1. “An air mass is an enormous body of air.”
→ TRUE. Air masses are huge — hundreds or thousands of miles across!

2. “Air masses take days to move into a new area.”
→ TRUE. They don’t zoom around — they drift slowly with wind patterns.

3. “Air masses form over water only.”
→ FALSE. They can form over land OR water. Over land = dry; over water = moist.

4. “The properties of an air mass change as it moves.”
→ TRUE. As it travels over different surfaces (like warm ocean or cold land), it picks up new traits.

5. “Warm air masses form near the equator.”
→ TRUE. The equator gets lots of sun → warm air → warm air masses.

6. “Cold air masses form near the poles.”
→ TRUE. Poles are icy and cold → cold air masses start there.

7. “A maritime tropical air mass is cool and moist.”
→ FALSE. “Maritime” means over water → moist. “Tropical” means warm → so it’s WARM and moist, not cool.

8. “Continental polar air masses are cold and dry.”
→ TRUE. “Continental” = over land → dry. “Polar” = near poles → cold. So yes, cold and dry.

9. “Air masses move from east to west in the United States.”
→ FALSE. In the U.S., most weather systems (including air masses) move from WEST to EAST because of prevailing winds.

10. “Air masses form over large, flat areas with uniform surface conditions.”
→ TRUE. That’s how they get consistent temp and moisture — like over a big ocean or desert.

✔ So answers for Part A:
1. T
2. T
3. F
4. T
5. T
6. T
7. F
8. T
9. F
10. T

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Part B: Label the map

We need to label 6 air masses on the map using these codes:

- cP = continental polar → cold & dry → forms over land near poles → usually Canada/Alaska
- mP = maritime polar → cold & moist → forms over cold oceans → North Pacific / North Atlantic
- cT = continental tropical → hot & dry → forms over deserts → Southwest U.S./Mexico
- mT = maritime tropical → warm & moist → forms over warm oceans → Gulf of Mexico / Caribbean / Southeast Atlantic
- cA = continental arctic → very cold & dry → forms over Arctic ice → northernmost Canada/Greenland
- mE = maritime equatorial → very warm & very moist → forms near equator over oceans → rarely affects U.S. directly, but sometimes shown off southern tip

Looking at typical U.S. air mass maps:

Top left (Canada): cP
Top right (North Atlantic): mP
Bottom left (Pacific near CA): mP (cold ocean current)
Bottom center (Gulf of Mexico): mT
Southwest (Arizona/Mexico): cT
Far north (Arctic): cA

*(Note: Some maps may show mE far south, but since it doesn’t affect U.S. much, often omitted. We’ll stick to the 6 common ones affecting North America.)*

So labeling the numbered spots on the map (assuming standard layout):

1. Northern Canada → cA
2. Alaska/NW Canada → cP
3. North Pacific → mP
4. Gulf of Mexico → mT
5. Southwest U.S./Mexico → cT
6. North Atlantic → mP

*(If your map has different numbering, match location to description above.)*

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Classification Table

Now fill in the table based on what we know:

| Air Mass | Source Region | Temperature | Moisture Content | Abbreviation |
|----------|----------------------|-------------|------------------|--------------|
| 1. Continental polar | Land near poles | Cold | Dry | cP |
| 2. Maritime polar | Ocean near poles | Cold | Moist | mP |
| 3. Continental tropical | Land near equator/deserts | Hot | Dry | cT |
| 4. Maritime tropical | Warm ocean | Warm | Moist | mT |
| 5. Continental arctic | Arctic land/ice | Very Cold | Very Dry | cA |
| 6. Maritime equatorial | Equatorial ocean | Very Warm | Very Moist | mE |

*(Note: Sometimes "continental arctic" is grouped under polar, but here it's listed separately. Also, maritime equatorial is rare for U.S. impact, but included for completeness.)*

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Final Answer:

Part A:
1. T
2. T
3. F
4. T
5. T
6. T
7. F
8. T
9. F
10. T

Part B (Map Labels – assuming standard positions):
1. cA
2. cP
3. mP
4. mT
5. cT
6. mP

Classification Table:
1. cP — Cold, Dry
2. mP — Cold, Moist
3. cT — Hot, Dry
4. mT — Warm, Moist
5. cA — Very Cold, Very Dry
6. mE — Very Warm, Very Moist