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Compare permanent with variable gasses. Give examples of each.
Permanent gases- remain at stable concentrations (78% N2, 21% O2, 1% Ar)
Variable gases- vary across time and place (water vapor 0-7%)
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Troposphere
- Closest to earth, 0-11
- kilometers high
- most dense
- the temperature decreases as altitude increases
- weather occurs in this region
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original atmosphere was composed of
H and He
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second atmosphere evolved from
gases from molten Earth
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modern Atmosphere evolved after
Cyanobacteria started photosynthesizing
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Atmosphere
- thin layer of gases around Earth
- Provides oxygen
- Absorbs radiation and moderates climate
- Transports and recycles water and nutrients
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Stratosphere
- extends from 11 to 50 kilometers highdry and less dense
- temperature in this region increases gradually due to the absorption of ultraviolet radiation
- ozone layer absorbs and scatters the solar ultraviolet radiation
- ninety-nine percent of "air" is located in first two layers
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Mesosphere
- Extends 50 – 80 km
- Coldest layer of the atmosphere
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Thermosphere
- Absorbs solar radiation
- temps reach 2,000 ºC
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Differentiate between weather and climate. What are some factors that influence climate?
- Weather is the state of the atmosphere at a particular time and place
- Climate is the long term weather conditions
- 2 main factors (Temperature, Precipitation)
- –atmospheric circulation, oceanic circulation, local geography, solar activity, and volcanic activity
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What is the most important factor in determining climate? Describe the patterns with this factor.
- Latitude- The distance from the equator measured in degrees N or S
- At any given latitude, variations occur due to factors such as altitude, proximity to a large body of water, ocean currents, and wind patterns.
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How do we get our seasons?
- The Sun Causes Seasonal Changes
- Occur because the earth’s axis is tilted (23.5º)
- Creates opposite seasons in the northern and southern hemisphere
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Describe the pattern of convective circulation.
- –less dense, warm, moist air rises
- –Rising air expands and cools
- –Cool air descends and becomes denser
- –Replacing rising warm air
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Name the three types of convective cells, their latitudes, patterns of circulation and how each affects biome distribution on our planet.
- Hadley cells = convective cells near the equator
- –Causing heavy rainfall and tropical rainforests
- They are responsible for the trade winds in the Tropics and control low-latitude weather patterns.
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Doldrums
a region near the equator with few winds
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Trade winds
- between the equator and 30 degrees
- Blow from east to west
- Weaken periodically, leading to El Niño conditions
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Ferrel cells and polar cells
- Ferrel cells (between 30-60 degrees)
- polar cells lift air and create precipitation at 60 degrees latitude north and south
- –Conditions at the poles are dry
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Westerlies
- from 30 to 60 degrees latitude
- Blow from west to east
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Thermal (temperature) inversion
- a layer of cool air occurs beneath warm air
- Inversion layer = the band of air where temperature rises with altitude- Denser, cooler air at the bottom of the layer resists mixing
- Inversions trap pollutants in cities surrounded by mountains ie LA
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Describe the Coriolis effect and how it affects global wind patterns.
- he apparent north-south deflection of air currents of the convective cells
- influences wind by deflecting its path to the right in the Northern Hemisphere
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Explain three natural sources of air pollution and two man-made sources:
- Volcanoes- Release particulate matter, sulfur dioxide, and other gases
- Fires- pollute the atmosphere with soot and gases
- Dust Storms- Wind over arid land sends huge amounts of dust aloft
- -Unsustainable farming and grazing promote Erosion and Desertification
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- Point sources = specific spots where large quantities of pollutants are discharged (power plants and factory)
- Non-point sources = more diffuse, consisting of many small sources (automobiles)
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Primary pollutants Secondary pollutants
- Primary pollutants = directly harmful and can react to form harmful substances
- -(soot and carbon monoxide)
- Secondary pollutants = form when primary pollutants interact or react with components of the atmosphere
- -Tropospheric ozone and sulfuric acid
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How does a pollutants residence time affect its impact?
- Pollutants with brief residence times exert localized impacts over short time periods
- -Particulate matter, automobile exhaust
- Pollutants with long residence times exert regional or global impacts
- -Pollutants causing climate change or ozone depletion
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Below explain the Clean Air Act and its amendments in 1990 and 1997.
- Set standards for air quality
- limits on emissions
- Provided funds for pollution-control research
- Allowed citizens to sue parties violating the standards
- The Clean Air Act of 1990 strengthened regulations for auto emissions, toxic air pollutants, acidic deposition, stratospheric ozone depletion
- Introduced emissions trading for sulfur dioxide
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Carbon monoxide (CO)
- colorless, odorless gas
- Produced primarily by incomplete combustion of fuel From vehicles and engines, industry, waste combustion, residential wood burning
- Poses risk to humans and animals, even in small concentrations
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Sulfur dioxide (SO2)
- colorless gas with a strong odor
- Coal emissions from electricity generation
- Can form acid precipitation
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Nitrogen dioxide (NO2)
- a highly reactive, foul-smelling reddish brown gas
- Nitrogen oxides (NO) = formed when nitrogen and oxygen react at high temperatures in engines Vehicles, industrial combustion, electrical utilities
- Contribute to smog and acid precipitation
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Tropospheric ozone (O3)
- a colorless gas with a strong odor
- Considered a pollutant in one part of the atmosphere but essential in another
- Results from interactions of sunlight, heat, nitrogen oxides, and volatile carbon-containing chemicals
- A secondary pollutant
- Harm tissues and cause respiratory problems
- The pollutant that most frequently exceeds EPA standards
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Particulate matter
- suspended solid or liquid particles
- Primary pollutants: dust and soot
- Secondary pollutants: sulfates and nitrates
- Damages respiratory tissue when inhaled
- From dust and combustion processes
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Lead
- in gasoline and industrial metal smelting
- accumulates and damages the nervous system
- Banned in gasoline in developed, but not in developing, countries
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Who sets standards for the six criteria pollutants? Who monitors them?
- State and local agencies monitor, calculate, and report to the EPA the emissions of criteria pollutants while agencies monitor them
- Tropospheric ozone has no emissions to monitor
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What are VOC’s? Where do they come from?
- Organic chemicals that vaporize readily and form toxic fumes
- Used and emitted by engines and industrial processes
- VOCs can react to produce ozone
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Define smog. Describe a few ways we can reduce smog.
- an unhealthy mixture of air pollutants over urban areas
- Regulations require new cars to have catalytic converters
- Require cleaner industrial facilities
- Financial incentives to replace aging vehicles
- Reduce sulfur in diesel; remove lead in gasoline
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industrial smog and photochemical smog
- Industrial (gray air) smog = industries burn coal or oil, Sulfur from burned coal combines with oxygen to form sulfuric acid
- Photochemical (brown air) smog = Produced by a series of reactions, Formed in hot, sunny cities surrounded by mountains, Light-driven reactions of primary pollutants and atmospheric compounds, Irritates eyes, nose, and throats
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What is a CFC? What produces them? What affect does a CFC molecule have on stratospheric ozone?
- a halocarbon used as refrigerants, in fire extinguishers, in aerosol cans, etc.
- CFCs remain in the stratosphere for a century
- UV radiation breaks CFCs into chlorine and carbon atoms
- The chlorine atom splits ozone
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Why is the ozone hole over Antarctica?
- A polar vortex (swirling winds) traps chlorine
- UV radiation in September (spring) sunshine dissipates the clouds and releases the chlorine
- The chlorine destroys the ozone
- the “ozone hole” occurs over Antartica because of the special atmospheric and chemical conditions that exist there and nowhere else on the globe.
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What was the Montreal Protocol? Why was it so successful?
- 196 nations agreed to cut CFC production in half by 1998
- Follow-up agreements deepened cuts, advanced timetables, and addressed other ozone-depleting chemicals
- It is considered our biggest environmental success story
- --Research developed rapidly, along with technology
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acid deposition
- the deposition of acid, or acid-forming pollutants from the atmosphere onto Earth’s surface
- Nutrients are leached from topsoil- Soil chemistry is changed
- Damages crops
- Affects surface water and kills fish
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What is the leading cause of indoor air pollution in developing countries?
burning wood, charcoal, dung, crop wastes inside homes with little to no ventilation
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Name and describe 4 common types of indoor air pollutants in developed countries.
- Cigarette smoke contains over 4,000 chemicals
- Radon- colorless, odorless gas resulting from natural decay of rock, soil, or water that can seep into buildings
- -- second leading cause of lung cancer, causes 21,000 deaths a year in the U.S.
- VOC- airborne carbon-containing compounds
- --“New car smell”- dozens of VOCs from plastics, metals, leather
- Living organisms can pollute indoors
- --Fungi, mold, mildew, airborne bacteria cause allergies, asthma, other respiratory ailments, and diseases
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What is sick building syndrome?
- a sickness produced by indoor pollution with general and nonspecific symptoms
- Reduced by using low-toxicity materials and good ventilation
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Explain 3 techniques for reducing indoor air pollutants in Developing countries Developed countries
- Developing: Dry wood before burning (reduces the amount of smoke produced)
- Cook outside
- Developed: limit use of plastics and treated wood, monitor air quality, keep rooms clean, Provide adequate ventilation, Limit exposure to pesticides, Test homes and offices for radon, mold and CO
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