Layers of the Atmosphere
- 2. Layers of the Atmosphere Weather and Climate
- 3. Layers of the Atmosphere There are 4 layers of the atmosphere Troposphere Stratosphere Mesosphere Thermosphere
- 4. Layers of the Atmosphere There are 3 boundaries between the layers Tropopause Stratopause Mesopause
- 5. Troposphere From the surface of the earth to about 10km above the earth’s surface All weather occurs in the troposphere Temperature gets cooler at a constant rate as altitude increases Tropopause : The boundary at the top of the troposphere. The low temperature (-55C) keeps the water vapor and clouds in the troposphere.
- 6. Troposphere Temperature Inversion: Warm air traps cooler air near the earth’s surface. The cooler air can not rise and it becomes very polluted. Where do we see examples of this phenomenon Denver , Salt Lake City and Los Angeles
- 7. Stratosphere 10km to about 50km above the earth’s surface Temperature gets warmer with increasing altitude No water vapor in the the stratosphere results in few clouds and no storms Stratopause: The boundary between the top of the Stratosphere and the bottom of the Mesosphere Ozone Layer: In the upper part Stratosphere and absorbs the sun’s ultra-violet radiation. How does the ozone layer affect us?
- 8. Mesosphere Extends from 50km to 80km above the earth’s surface Temperatures decrease with increasing altitude At the top of the mesosphere is the coldest part of the earth’s atmosphere where temperatures drop below -80 degrees C Mesopause: The boundary between the top of the Mesosphere and the bottom of the thermosphere
- 9. Thermosphere Extends from 80km to 480km above the earth’s surface. Temperatures increase with an increase in altitude and become very hot Average temperature is 980 degrees C (1796 F) Ionosphere: lower portion of the thermosphere where Auroras occur
- 10. Aurora Borealis in Alaska
- 11. Changes in Earth’s Atmosphere Early Earth : 4.4 billion years ago to 2.5 billion years ago As the earth began to solidify, volcanic eruptions released gases in a process call outgassing Early Earth Atmosphere was mainly composed of: carbon dioxide (CO2), nitrogen, ammonia (NH3), methane (CH4), H20 and other trace gases NO free oxygen ! The earth’s early atmosphere would be poisonous to us today!
- 12. Changes in Earth’s Atmosphere About 2.5 billion years ago bacteria and other single-celled organisms began using photosynthesis to change sunlight into food. This process released oxygen into the air and gradually changed the earth’s atmosphere. About 350 million years ago the atmosphere reached its current composition What two elements make up most of the earth’s atmosphere today? Current atmosphere is mainly composed of: nitrogen (about 78%), oxygen (about 21%), and trace gases.
- 13. Greenhouse Effect A process in which atmospheric gases trap some of the energy from the sun in the troposphere. This helps to keep the earth warm. How the Greenhouse Effect works: Solar radiation warms the earths surface and returns to the atmosphere as heat radiation. Greenhouse gases (CO2 + H2O) in the atmosphere trap some of the heat radiation and it radiates back towards Earth. Forest fires and the burning fossil fuels adds more CO2 to the atmosphere. This traps more heat radiation in the troposphere. An increase in the amount of heat radiation in the troposphere is a possible cause of……? Global Warming
- 14. Exit Slip Individual Non-Stop Write: Write non-stop for 2 minutes answering the question: What do you know about the layers of the atmosphere? Do your best to fill your exit slip with complete sentences to explain your understanding of the atmosphere. Keep writing for the entire 2 minutes! If you need to, write questions and predictions to keep writing! Please write any questions/concerns/predictions you might have about weather and the atmosphere on the back of your card!
- 15. Videos Antarctica Auroras Space Auroras Greenhouse