Learn on PengiAmplify Science (California) Grade 5Chapter 3: Why is more water vapor getting cold over West Ferris than East Ferris?

Session 2: Temperature and Altitude

Key Idea.

Section 1

The Higher, The Colder

Key Idea

You might think that getting closer to the sun would make the air warmer, but in our atmosphere, the opposite is true. As you go up, it gets colder.

We call the height above the ground altitude. There is a predictable pattern: as altitude increases, air temperature decreases. This is why tall mountains have snow on their peaks even when it is hot at the beach below.

Section 2

Heat Comes from the Ground

Key Idea

Why is it colder up high? The sun mainly warms the Earth's surface (land and water), not the air directly.

The air warms up because it is touching the warm ground. As air moves higher, it moves farther away from its heat source (the ground). Therefore, the air at high altitudes loses heat and becomes much colder than the air near the surface.

Section 3

The Freezing Line

Key Idea

Because the atmosphere gets colder as you go up, there is a specific layer in the sky where the air becomes cold enough to freeze water.

Below this line, water might exist as liquid or gas. Above this line, at very high altitudes, the temperature is so low that water vapor can turn directly into ice crystals. This change in temperature with height is critical for weather.

Lesson overview

Expand to review the lesson summary and core properties.

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Section 1

The Higher, The Colder

Key Idea

You might think that getting closer to the sun would make the air warmer, but in our atmosphere, the opposite is true. As you go up, it gets colder.

We call the height above the ground altitude. There is a predictable pattern: as altitude increases, air temperature decreases. This is why tall mountains have snow on their peaks even when it is hot at the beach below.

Section 2

Heat Comes from the Ground

Key Idea

Why is it colder up high? The sun mainly warms the Earth's surface (land and water), not the air directly.

The air warms up because it is touching the warm ground. As air moves higher, it moves farther away from its heat source (the ground). Therefore, the air at high altitudes loses heat and becomes much colder than the air near the surface.

Section 3

The Freezing Line

Key Idea

Because the atmosphere gets colder as you go up, there is a specific layer in the sky where the air becomes cold enough to freeze water.

Below this line, water might exist as liquid or gas. Above this line, at very high altitudes, the temperature is so low that water vapor can turn directly into ice crystals. This change in temperature with height is critical for weather.