Composition of the Atmosphere (ATM) The atmosphere is a mixture of gases that surrounds Earth Earth has a unique ATM – no other planet in the solar system has an ATM with the exact mixture of gases

*Most Important Trace Gas - Ozone Composition Gases 78% Nitrogen 21% Oxygen Remaining 1%: Argon, Carbon Dioxide, Trace Gases* Water Vapor (the amount of water in the air) Dust, dirt, smoke, volcanic ash, sea salt *Most Important Trace Gas - Ozone

Structure of the Atmosphere 4 Layers (5 including Exosphere) 99% of Earth’s atmosphere is within 30 km of Earth’s surface. Changes in temperature separate the layers

1. Troposphere: ~0-10km Contains most of the mass of the ATM including water vapor We are in this layer, where all weather occurs Temperature decreases with increasing altitude Tropopause: boundary between the troposphere and the stratosphere

2. Stratosphere: ~10-50km A layer made up primarily of concentrated ozone The ozone layer is protects life on Earth by absorbing UV rays Temperature increases with increasing altitude Stratopause: boundary between the stratosphere and the mesosphere

3. Mesosphere: ~50-80km Temperature decreases with increasing altitude (The coldest layer in the ATM) Where meteors tend to burn up Mesopause: boundary between the mesosphere and the thermosphere

Contains only a minute portion of the ATM’s mass 4. Thermosphere: ~80km+ Contains only a minute portion of the ATM’s mass Subdivided into exosphere and the ionosphere Temperature increases with increasing altitude (Has the highest temperature in the ATM) High temperatures are the result of incoming solar radiation Auroras happen here!

Exosphere: Exo means outside Outermost layer of earths ATM Sometimes called the Ionosphere Reaches up to 10,000 km Temperatures are anywhere 0-1,700 C Where the International Space Station orbits Earth

Layering of the ATM Plot and connect all data points on your graph Draw a line and label each layer, including the boundaries that are in-between