env 17a

  1. Atmosphere
    the thin layer of gases that surrounds Earth

    • -Absorbs radiation and moderates climate
    • -Transports and recycles water and nutrients
    • -78% nitrogen gas, 21% oxygen gas, 1% other gases
    • -Its four layers differ in temperature, density and composition
  2. Troposphere
    • bottommost layer
    • Air for breathing, weather
    • Temperature declines with altitude
  3. Tropopause
    limits mixing between troposphere and the layer above it
  4. Stratosphere
    • 11-50 km (7-31 mi) above sea level
    • Drier and less dense, with little vertical mixing
    • Colder in its lower regions
    • Contains UV radiation-blocking ozone, 17-30 km (10-19 mi) above sea level
  5. Mesosphere
    -Extremely low air pressure

    -Temperatures decrease with altitude
  6. Thermosphere
    • •atmosphere’s top layer
    • -Extends upward to 500 m (300 mi)
  7. Atmospheric Pressure
    •measures the force per unit area produced by a column of air

    -Decreases with altitude
  8. Relative Humidity
    the ratio of water vapor a given volume of air contains to the amount it could contain at a given temperature
  9. Convective Circulation
    • less dense, warmer air rises and creates vertical currents
    • -Rising air expands and cools
    • -Cool air descends and becomes denser, replacing warm air
    • -Influences both weather and climate
  10. Front
    the boundary between air masses that differ in temperature, moisture, and density
  11. Cold/Warm Front
    the boundary where colder, drier air displaces warmer, moister air

    the boundary where warm moist air replaces colder, drier air
  12. High Pressure System
    air that moves away from a center of high pressure as it descends

    Brings fair weather
  13. Low Pressure System
    air moves toward the low atmospheric pressure at the center of the system and spirals upward
  14. Thermal Inversion
    a layer of cool air occurs beneath a layer of warmer air
  15. Inversion Layer
    band of air in which temperature rises with altitude
  16. Hadley Cells
    • near the equator, surface air warms, rises, and expands
    • Releases moisture and heavy rainfall near the equator
  17. Ferrel Cells and Polar Cells
    • •lift air
    • -Creates precipitation at 60 degrees latitude north and south
    • -Causes air to descend at 30 degrees latitude
  18. Corialis Effect
    the north-south air currents of the convective cells appear to be deflected from a straight path
  19. Doldrums
    • near the equator
    • -Few winds
  20. Trade Winds
    between the equator and 30 degrees latitude
  21. Westerlies
    from 30 to 60 degrees latitude

    Originate from the west and blow east
  22. Air Pollutants
    gases and particulate material added to the atmosphere
  23. Air Pollution
    the release of pollutants
  24. Aerosolis
    reflect sunlight back into space and cool the atmosphere and surface
  25. Point Sources
    specific spots where large quantities of pollutants are discharged (power plants and factories)
  26. Nonpoint Sources
    more diffuse, consisting of many small sources (automobiles)
  27. Primary Pollutants
    directly harmful and can react to form harmful substances (soot and carbon dioxide)
  28. Secondary Pollutants
    • form when primary pollutants interact or react with constituents or components of the atmosphere
    • (tropospheric ozone and sulfuric acid)
  29. Criteria Pollutants
    pollutants judged to pose especially great threats to human health
  30. Carbon Monoxide
    • -A colorless, odorless gas
    • -Produced primarily by incomplete combustion of fuel
    • -Poses risk to humans and animals, even in small concentrations
Card Set
env 17a