Do Now Put the layers of the atmosphere in order: (stratosphere, thermosphere, troposphere, mesosphere). In which layer do we live? In which layer is the ozone layer found? Which layer is in the middle (how can we remember this?) What happens to air pressure the higher you go up?

Layers of the Atmosphere Compare the composition and structure of Earth’s atmospheric layers (including the gases and differences in temperature and pressure within the layers).

Layers of the Atmosphere The atmosphere is the layer of gases that surrounds the planet and makes conditions on Earth suitable for living things.

1. Troposphere The troposphere is where all the weather occurs. It is the closest layer to Earth’s surface. It is the layer we live in. Higher altitude = colder temps.

2. Stratosphere The stratosphere is located directly above the troposphere. This is where the ozone layer is. Ozone is 3 oxygen molecules (formula = O3) Higher altitude = hotter temps.

3. Mesosphere The mesosphere is located directly above the stratosphere. This is where meteors and comets are destroyed. COLDEST LAYER (higher altitude = colder temps.)

4. Thermosphere Hottest layer of the atmosphere! Where the Northern Lights are located.

Atmospheric Gases Nitrogen & Oxygen These are the two most common gases found in the atmosphere. They can be found throughout all the layers. Nitrogen: 78% Oxygen: 21% Other: 1%

Atmospheric Gases Ozone Ozone is a form of oxygen It is only found in the stratosphere Ozone is a gas formed by the addition of a third oxygen atom to an oxygen molecule. It is important in the upper atmosphere because it absorbs ultraviolet radiation from the sun. Without an ozone layer, our skin could not tolerate exposure to the Sun.

Atmospheric Gases Water Vapor & Carbon Dioxide (CO2) These are important gases for weather conditions. They are found in the troposphere where weather occurs.

Atmospheric Temperatures Differences in temperature are what separate each layer in the atmosphere from the one above and/or below it. Example: the troposphere is a different temperature than the stratosphere

Atmospheric Temperatures Temperature Altitude Outer Space Exosphere Thermosphere Mesosphere Stratosphere Troposphere Earth’s Surface

Atmospheric Pressure Air pressure is how much force gases place on an object Air pressure is greatest near the surface of the Earth in the troposphere because of gravity Altitude Air Pressure

Pause What is the Tropopause? What is the Stratopause? The upper limit of the troposphere What is the Stratopause? The upper limit of the stratosphere What is the Mesopause? What is the Thermopause?

Atmospheric Temperatures In the troposphere: As altitude increases, temperature decreases *** remember, increase means go UP, and decrease means go DOWN! Temperature Altitude

Atmospheric Temperatures In the stratosphere: The stratosphere is cold except in its upper region where ozone is located. Temperature Altitude Ozone Layer

Atmospheric Temperatures In the Mesosphere: This is the COLDEST layer in the atmosphere. Temperature Altitude

Atmospheric Temperatures In the thermosphere: Even though the air is thin in the thermosphere, it is very HOT. Temperature Altitude

2 Activity Choices (CHOOSE 1) Write a “Thank you” note to the layers of the atmosphere thanking each layer for what it does for us Thank each layer for what they do for us (lets us breathe, protects us from skin cancer, burns up comets, gives us light shows, etc.) 1 full page long – BE CREATIVE Create a 15 question practice quiz and answer key to help a classmate study