Characteristics of the Atmosphere A mixture of gases that surrounds a planet or moon Air pressure The measure of the force with which air molecules push on a surface
Air Pressure Gravity pulls gas molecules in atmosphere toward Earth, causing air pressure As altitude ↑, air pressure ↓
Layers of the Atmosphere Based on temperature changes Temperature changes b/c gases absorb solar energy differently
Thermosphere Mesosphere Stratosphere Troposphere Earth
Troposphere “turning, changing” layer Densest atmospheric layer Almost all Earth’s H2O vapor, clouds, air pollution, weather, life-forms As altitude ↑ the temperature ↓
Stratosphere “layer” Home of the ozone layer As altitude ↑ temperature ↑ b/c ozone absorbs heat energy from sun, (therefore heating up the surrounding area) Ozone layer protects life on Earth by absorbing UV light
Mesosphere “middle” Coldest layer As altitude ↑ temperature ↓
Thermosphere “heat” As altitude ↑ temperature ↑ Ionosphere is here (NORTHERN LIGHTS, AURORAS) International Space Station orbits in this layer