Earth's Atmosphere Layers PDF - Science Notes

Earth’s Atmosphere Let’s keep the balance! What is the Atmosphere? Atmosphere Thin layer of air (gases) that forms a protective covering around Earth Importance of the Atmosphere Provides life Gives protection Insulates from extreme temperatures Earth The Moon...

Earth’s Atmosphere Let’s keep the balance! What is the Atmosphere? Atmosphere Thin layer of air (gases) that forms a protective covering around Earth Importance of the Atmosphere Provides life Gives protection Insulates from extreme temperatures Earth The Moon What differences do you see? Makeup of the Atmosphere Earth’s early atmosphere Created by erupting volcanoes Contained nitrogen and CO2; little oxygen Early organisms released oxygen and created a layer rich in ozone (O3) Gasses in the atmosphere Nitrogen – 78% Oxygen – 21% Trace elements – 1% (Argon and CO2) Makeup of the Atmosphere Makeup of the Atmosphere Solids Dust – picked up by wind Salt – picked up from ocean spray Pollen – given off from plants Liquids Water droplets in clouds Liquid droplets from volcanoes Sulfuric acid droplets  Layers of the Atmosphere “The Sky Meets The Earth” The layers of the atmosphere are defined by changes in temperature Troposphere Lowest layer We live in this layer Contains 80% of the total mass of the atmospheric gases Airplanes Weather Temperature decreases as you rise in altitude Stratosphere Above the troposphere Temperature increases with altitude b/c of OZONE Ozone Concentrated at 25 kilometers Absorb dangerous UV radiation Jet streams occur here Ozone Layer Within stratosphere About 19 to 48 km in altitude Ozone is made up of 3 oxygen atoms (O3) Absorbs and protects us from UV radiation Too much UV ray exposure can cause tissue damage (skin cancer) CFCs CFCs = Chlorofluorocarbons Human-made chemicals that destroy ozone Produced by: Air conditioners Refrigerants Styrofoam Cleaning electronics Propellants CFCs can stay in the atmosphere and cause damage for up to 100 years! UV radiation When ozone is destroyed UV radiation increases Over exposure causes: Sunburn and skin cancer Cataracts Weakening of the immune system Ozone in the Troposphere In the troposphere, ozone is a pollutant Exposure to ozone affects: Crop production Forest growth Human health The Ozone Hole Destruction of ozone molecules by CFCs causes a seasonal reduction in ozone over Antarctica Smallest in October B/C of ozone hole appearance, many governments banned the production and use of CFCs in the late 80’s The Good News Many countries have banned the production and use of CFCs (late 80’s) Mother Nature should be able to “fix” the ozone layer by about 2065 Wearing sunscreen helps block UV rays Satellites, the space shuttle and auroras occur in the thermosphere “Falling Stars” occur in the mesosphere Mesosphere Most falling stars (meteors) burn up in this layer Temperature decreases as you rise in altitude Coldest temperatures (-90°C) Air is extremely thin Noctilucent clouds Thermosphere Air is extremely thin Temperature is sensitive to solar activity – 1,500°C or higher! Gamma and X-ray radiation absorbed Molecules blend into space Northern Lights Exosphere Outermost layer Region where atoms and molecules escape into space (air is so thin it is basically nonexistent) Space shuttle, satellites and space station orbit in this layer The exosphere blends into true “outer space”