Layers of Atmosphere Slides for Earth Environmental.ppt
- 1. LAYERS OF GASES SURROUNDING EARTH LAYERS OF GASES SURROUNDING EARTH Atmosphere
- 2. % of gases in the atmosphere % of gases in the atmosphere • 78% Nitrogen • 21% Oxygen • 0.04% Carbon dioxide, CO2 • 0.4% water vapor
- 3. • Gravity pulls the gases of atmosphere toward earth’s surface & holds them • Most gases are found within 32 km (20 miles) • Air (atmospheric) pressure – pressure exerted on a surface by the atmosphere • Less air at higher altitudes means less weight pushing down = Air pressure is HIGHER at LOWER altitudes & Lower at Higher altitudes
- 4. 5 Layers 5 Layers of the Atmosphere of the Atmosphere Layers are divided by Layers are divided by TEMPERATURE! TEMPERATURE!
- 5. 1) Troposphere 1) Troposphere • Layer closest to the Earth (sea level to 10 miles) • Contains 90% of the atmosphere’s mass, making it the MOST DENSE LAYER! • Temperature decreases as altitude increases • Contains almost all of the CO2, water vapor, clouds, weather, air pollution
- 6. 1) Troposphere 1) Troposphere Warmest temperatures at the bottom Temperatures decrease with height Top layer is called the tropopause
- 7. 2) Stratosphere 2) Stratosphere • Above Troposphere (10-30 miles) • Very little water vapor or clouds • Absorbs UV radiation from sun • Temps increase as altitude increases • Contains Ozone: made of 3 oxygen molecules (not the usual 2)
- 8. Ozone Ozone Center region of stratosphere is called the OZONOSPHERE Ozone molecules ABSORB UV rays from the Sun Temperature increases
- 9. Ozone Ozone • Ozone layer is reduced by chemical interaction with CFCs (Chlorofluorocarbons) which are released from refrigerators, air conditioners, and aerosol cans.
- 10. 3) Mesosphere 3) Mesosphere • Sits on top of stratopause • Temperatures decrease with height- it is the coldest layer of the atmosphere reaching -130 F – (-93o C) • Protects Earth’s surface from meteoroids
- 11. 4) Thermosphere 4) Thermosphere • layer above Mesosphere • Little atmosphere, very low density • Temperatures increase with altitude reaching 3,632o F due to decreasing air
- 12. 4) Thermosphere 4) Thermosphere • Contains Ionosphere- lower layer of thermosphere, energy from Sun tears gasses apart, electrically charging particles • This releases lights that we call the Aurora borealis!
- 13. 5) Exosphere 5) Exosphere • Exosphere - uppermost layer • Space shuttle orbits here • Temperature increases with altitude before blending into space • Composition of Oxygen, Nitrogen, and Helium
- 14. Solar Energy Solar Energy • Our atmosphere is heated by the transfer of energy from the sun in several ways: • A) radiation – all forms of energy from waves in space ex. radio, infrared, visible, ultraviolet (UV), & X-rays • B) conduction – when heat (E) is transferred from 1 object to another by direct contact • C) convection – the movement of GASES or LIQUIDS when they are heated unevenly
- 15. • Most solar energy that reaches the Earth’s atmosphere is ABSORBED by the surface • Solar – energy from the sun is trapped in the lower atmosphere by “greenhouse gases” & prevented from escaping back into space • Greenhouse gases: – CO – burning of wood & fossil fuels – CO2 – use of coal, natural gas, & oil – CH4 – farming and industrial activity
- 16. Global Warming Global Warming • Energy trapped by gases in our atmosphere has caused the overall global temperature of Earth to rise over the past 100 years. • Human activity such as burning fossil fuels & deforestation, may be increasing the levels of greenhouse gases in our atmosphere
- 17. Wind Wind • Wind- movement of air due to uneven atmospheric pressure • Coriolis Effect – rotation of Earth causes surface winds in the Northern Hemisphere to turn to the LEFT and surface winds in the Southern Hemisphere to the RIGHT
- 18. • When air gets warmer it becomes less dense, as it rises it begins to move toward the POLES. • The longer it is high in the air, it becomes More DENSE and SINKS down to the Earth’s surface again where it is warmed. • Air flowing from the equator completes Continuous looping patterns of flow called “wind cells.”