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mesosphere

thermosphere

The Atmosphere Mixture of gases that surround Earth There are 4 layers in the atmosphere that

are divided based on their temperature gradient. troposphere, stratosphere mesosphere, thermosphere

4 Layers1) Troposphere – layer in which

we live; Weather phenomena (clouds) occur here. It’s elevation ranges from 0 to 10 km

2) Stratosphere – above troposphere; temperatures increase with altitude. This layer contains the ozone layer, which

protects us from harmful sunlight

What are the layers in the atmosphere? (cont…)

Mesosphere – coldest layer of atmosphere

Thermosphere – uppermost layer; temperatures also increases with altitude. This is where most small meteorites burn

up the location in the atmosphere that the

northern lights occur (aurora borealis)

Structure of the Atmosphere

Thermosphere

Mesosphere

Ozone MaximumStratosphere

Troposphere

Temperature

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Why is the atmosphere important?

80% of atmospheric gases are in the 15 km closest to Earth. This is a very thin layer compared to the Earth’s diameter, which is 12,756 kilometers.

The Earth is different than the other planets in our solar system because it has an atmosphere that can support life.

The atmosphere is an envelope of different gases (air) surrounding Earth.

mesosphere

thermosphere

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What is the atmosphere made of?

The gases that make up the atmosphere are:

about 78% is nitrogen

about 21% is oxygen

the remaining 1% is mostly argon (0.93%)

with some carbon dioxide (0.035%), varying amounts of water vapor and

trace amounts of other gases

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Does Earth’s atmosphere change?

About 3.5 billion years ago, the atmosphere on Earth would have been similar to the atmosphere on Mars today.

What theories are used to explain how the Earth’s atmosphere changed?

It would have contained large quantities of carbon dioxide, but not much oxygen or nitrogen.

The current composition of the air has been roughly the same for nearly 200 million years, but the amounts of different gases have changed over time.

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The history of the atmosphere

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Evolving atmosphere