The weather layer

The idea

The troposphere, about 12 km high on average (highest over the equator, lowest over the poles), is heated from the surface, its temperature falls with height (~6.5 °C/km), and nearly all weather occurs in it.

Where do clouds live?

Rain, storms and clouds all happen in the sky above us.

In which part of the air do you think nearly all of this weather occurs?

• The layer closest to the ground
• A layer far out near space
• All layers equally

The lowest layer

Open every tab.

The layer we live in

The troposphere sits right on the ground, so the ground heats it from below. Warm air rises, and that gives wind, clouds and storms. Higher up, the air is colder.

The troposphere, about 12 km high on average (highest over the equator, lowest over the poles), is heated from the surface. Its temperature falls with height (about 6.5 °C per km) and nearly all weather occurs in it.

Notes

The troposphere is about 12 km high, heated from the surface, colder with height (about 6.5 °C per km), and holds nearly all weather.

Check yourself

In which layer does nearly all weather occur?

What heats the troposphere?

In the troposphere, temperature falls by about 6.5 °C per km. About how many °C colder is the air 4 km above the ground?

Answer: 26 °C

For example, air at the ground is 30 °C. About what is the temperature 2 km above, using 6.5 °C per km?

Answer: 17 °C

• The stratosphere. In the stratosphere temperature rises with height, which calms the layer and keeps weather confined to the troposphere.
• The mesosphere. The mesosphere, thermosphere and exosphere play only a minor role in regulating climate on the surface.
• The troposphere — correct. Yes!
• The Earth's surface — correct. Yes!
• The ozone layer. The ozone layer is in the stratosphere. The troposphere is heated from the Earth's surface.
• Outer space. The troposphere is heated from the Earth's surface.