psc quick reference-Atmosphere

Atmosphere

• The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity.

• Mainly divided into 4 layers

1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere

Troposphere:

• The layer of the atmosphere closest to the earth is the troposphere.

• This layer is where weather occurs.

• It begins at the surface of the earth and extends out to about 4-12 miles.

• The temperature of the troposphere decreases with height.

• This layer is known as the lower atmosphere.

Stratosphere:

• Above the troposphere is the stratosphere, which extends to about 30-35 miles above the earth's surface.
•  Temperature rises within the stratosphere but still remains well below freezing.
• Ozone layer seen in this layer.
• Air travel occurs in this layer.

Mesosphere:

• From about 35 to 50 miles above the surface of the earth lies the mesosphere, where the air is especially thin and molecules are great distances apart. 
• Temperatures in the mesosphere reach a low of -184°F (-120°C). The stratosphere and the mesosphere are the middle atmosphere.

Thermosphere :

• The thermosphere rises several hundred miles above the earth's surface, from 50 miles up to about 400 miles. 
• Temperature increases with height and can rise to as high as 3,600°F (2000°C). 
• Nonetheless, the air would feel cold because the hot molecules are so far apart. 
• This layer is known as the upper atmosphere.
• Ionosphere is a part of this layer

Exosphere:

• Extending from the top of the thermosphere to 6200 miles (10,000 km) above the earth is the exosphere. 
• This layer has very few atmospheric molecules, which can escape into space.