Earth's Atmosphere Layers

Atmospheric Gases

• Nitrogen makes up 78% of the atmospheric gases, most common and abundant atmospheric gas
• Oxygen is the second most common atmospheric gas, making up 21% of atmospheric gases

Atmospheric Layers

• The troposphere is the lowest layer of the Earth's atmosphere, where weathering occurs

Stratosphere

• The stratosphere is the second layer of Earth's atmosphere, home of the ozone layer
• Ozone is a gas found in the stratosphere that protects earth from ultraviolet radiation from the sun

Mesosphere

• The mesosphere is the third layer of Earth's atmosphere, coldest layer and meteors burn up in this layer

Thermosphere

• The thermosphere is the fourth layer of the atmosphere, hottest layer, air very thin, energy from the sun strikes this layer first

Gravity and Air Pressure

• Gravity is the force that holds the Earth's atmosphere around Earth, creating air pressure
• Air pressure is a measure of the force with which air molecules push on Earth, caused by Earth's gravitational pull, is greatest (strongest) at the Earth's surface (sea-level) and decreases with altitude

Exosphere

• The exosphere is the outermost layer of the Earth or outer layer of the thermosphere, where communication satellites orbit