THE ATMOSPHERE: COMPOSITION AND LAYERS

• Atmosphere


  A thin layer of air that protects the Earth's surface from extreme temperatures and harmful sun rays
• Air


  • A mixture of several, colorless, odorless, and tasteless gases held by the Earth's gravity
• Gases in the atmosphere

  • Nitrogen
  • Oxygen
  • Argon
  • Carbon dioxide
  • Other gases
• Nitrogen


  The most abundant gas in the atmosphere, a gas which does not enter into chemical combination easily
• Oxygen


  The second most abundant gas, important to living organisms
• Argon


  An inert, colorless and odorless gas that only makes up about 1% of the Earth's atmosphere, a noble gas (not very reactive)
• Carbon dioxide


  A raw material for photosynthesis in plants
• Aside from gases, moisture and particulate matter like salt particles, pollen grains, spores, and microorganisms are also present in the atmosphere
• 5 Layers of the atmosphere


  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere

  
• Troposphere


  • Lowest layer, extends up to 8-10 km high, nearest layer to the Earth's surface, densest layer, clouds of all types and weather are formed here

  
• Stratosphere


  • The layer directly above troposphere, upper layer contains high levels of ozone, the ozone layer is found here, many jets and aircrafts are suited to fly here

  
• Mesosphere


  Meteors or rock fragments burn up in this layer, coldest layer with little ozone

  
• Thermosphere


  • a layer with Auroras, known for its high temperature, the ionosphere (layer of charged particles) is located here, it helps carry radio waves

  
• Exosphere


  • The upper limit of our atmosphere, outer layer where space shuttle orbit
• Greenhouse effect


  The natural warming of the earth attributable to the presence of atmospheric gases (15oC)
• Greenhouse gases


  The gases in the atmosphere that absorb radiation
• Global warming


  The current increase in temperature of the Earth's surface (both land and water) as well as its atmosphere, average temperatures around the world have risen by 0.75°C (1.4°F) over the last 100 years about two thirds of this increase has occurred since 1975