Unit 6: Atmospheric Systems & Society Flashcards
What are the 3 main gases in our atmosphere?
- nitrogen
- oxygen
- argon, ozone, CO2, water vapor, etc.
What percent of our atmosphere is made up of nitrogen?
78%
What percent of our atmosphere is made up of oxygen?
21%
What percent of our atmosphere is made up of argon, ozone, CO2, water vapor, etc.?
1%
How do we divide our atmosphere into 4 layers? (what factor determines how we divide our atmosphere)
temperature
What are the four layers of the atmosphere? (from lowest level of elevation to highest)
troposphere, stratosphere, mesosphere, thermosphere
troposphere
the layer closest to the Earth’s surface
How much of the atmosphere’s mass does the troposphere contain?
75%
In which layer of the atmosphere do most of the clouds/weather exist?
troposphere
How are temperature and pressure affected as you travel up the troposphere?
temperature and pressure drop
How far does the troposphere extend from the Earth’s surface?
about 10-15 km
In the stratosphere, why does temperature increase with altitude?
- the ozone layer absorbs the greater part of the solar ultraviolet radiation
- the air in the stratosphere is much less dense (thinner) than in the troposphere, so it doesn’t take as much energy to warm this air as it would to warm denser air closer to the ground
How far does the stratosphere extend from the Earth’s surface?
about 15-50 km
How far does the mesosphere extend from the Earth’s surface?
about 50-80 km
In the mesosphere, how is temperature affected with an increase in altitude?
temperature decreases
What unique process occurs in the mesosphere?
meteors burn up
How far does the thermosphere extend from the Earth’s surface?
about 80-320 km
Despite having hot temperatures, why would the thermosphere feel very cold to us?
this layer of the atmosphere is very thin, meaning there are not enough gas molecules to transfer heat to you
What two natural processes does our atmosphere do?
- greenhouse effect
- ozone shield/ozone layer
What does the greenhouse effect do?
keeps the planet warm by trapping long wave radiation from the planet
What does the ozone shield do?
blocks unwanted UV radiation, protecting life on Earth from cataracts, skin cancer, etc.
Why do temperature and pressure decrease with increasing altitude in the troposphere?
the gases in the troposphere do not absorb/emit solar radiation, instead the Earth’s surface absorbs this radiation; therefore, as a result of conduction and convention, the tropospheric heat is most concentrated at lower altitudes
Why does temperature decrease with increasing altitude in the mesosphere?
There are fewer gas molecules to absorb the Sun’s radiation (no ozone layer)
Why does the thermosphere get so hot?
the few molecules that are present in the thermosphere receive extraordinary amounts of of energy from the Sun, causing the layer to warm to high temperatures
What 2 abiotic factors cause changes in our atmosphere?
- temperature
- precipitation
Why is it important to use many forms of proxy data?
the accuracy of any particular one cannot be counted on 100% of the time
What 2 biotic factors cause changes in our atmosphere?
- plants
- animals
proxy data
preserved physical characteristics of the environment that can stand in for direct measurements
How can we measure the concentration of ancient atmospheric gas?
ice cores (bubbles trapped in ice)
What are 3 examples of proxy data?
- tree rings
- pollen fossils
- sediments
Without the greenhouse effect, how much cooler would the Earth be?
33°C cooler (91.4°F)
What does our average temperature allow for in terms of water?
our average temperature allows water to be liquid
What percent of incoming solar radiation is absorbed, scattered, or reflected by the atmosphere and clouds before it reaches the Earth’s surface?
almost 50%
What percent of incoming solar radiation reaches the Earth’s surface?
55%
What happens to the 55% of incoming solar radiation that reaches the Earth’s surface?
4% is reflected and 51% is absorbed in processes like photosynthesis, heating the ground and seas, and evaporation
What is incoming solar radiation mostly made up of?
visible light, UV light, and infrared light
How many bonds must greenhouse gas molecules have?
2 or more bonds
What are 4 greenhouse gases?
- water vapor (H2O)
- carbon dioxide (CO2)
- methane (CH4)
- ozone (O3)
ozone
a molecule made up of 3 oxygen atoms
How does ozone protect life on Earth?
ozone blocks incoming ultraviolet radiation
At what altitude are the highest ozone concentrations?
20-40 km
How is the ozone layer an example of a dynamic equilibrium?
ozone is continuously made from oxygen atoms and is continuously converted back to oxygen
How many parts per million is the ozone layer?
1-10 ppm
In what 2 layers of the atmosphere is ozone found?
the stratosphere (good) and the troposphere (bad)
How can UV radiation be absorbed in both the formation and destruction of ozone?
O2 is split under the influence of UV radiation resulting in two individual oxygen atoms, which can combine with another O2 to form ozone (O3); ozone can also absorb radiation and split into an oxygen molecule (O2) and and oxygen atom (O)
UV-C radiation
highest energy (shortest wave-length) and is therefore the most harmful type of radiation
How much UV-C radiation does the ozone layer absorb?
more than 90%
How much UV-B radiation does the ozone layer absorb?
about 50%
UV-A radiation
relatively harmless, low energy (longer wavelength)
What is the wavelength of UV-A radiation?
315-400 nm
What is the wavelength of UV-B radiation?
280-315 nm
What is the wavelength of UV-C radiation?
100-280 nm
What are 4 beneficial effects of radiation?
- stimulates the production of vitamin D
- can be used to treat skin diseases like vitiligo or psoriasis
- can be use to sterilize
- industrial uses like lasers, forensic analysis, or lighting
What are 7 damaging effects of radiation?
- genetic mutations
- damage to living tissues
- cataract formation in eyes
- skin cancer
- suppresses immune system
- damages phytoplankton
- damages zooplankton
How long have scientists been measuring the amount of ozone in the stratosphere above Antarctica?
since the 1950s
What did scientists observe in regards to the ozone in the stratosphere above Antarctica?
the amount of ozone decreased significantly during the spring and increased again in November
During the last 30 years, how has the ozone layer above Antarctica changed?
the minimum thickness of the ozone layer has reduced drastically and recovery is taking longer
What is ozone depletion mostly caused by?
air pollution by human-made chemicals
What are the 5 ozone depleting gases?
- CFCs (Chlorofluorocarbons)
- HCFCs (Hydrochlorofluorocarbons)
- halons
- methyl bromide
- nitrogen oxides
When were CFCs developed?
1930s
What were CFCs used as? (5 things)
- propellants in aerosols
- expanders of gas-blown plastics
- pesticides
- flame retardants
- refrigerants
How long does it take CFCs to reach the stratosphere?
10-20 years
How many chlorine atoms from CFC does it take to convert 100,000 molecules of ozone to oxygen?
1 chlorine atom
Montreal Protocol
international agreement to phase out the production of ozone-depleting substances
What are 4 examples of strategies for reducing ozone-depleting substances by altering the human activity producing pollution?
- replace gas-blown plastics
- replace CFCs with carbon dioxide, propane, or air as a propellant
- replace aerosols with pump action sprays
- replace methyl bromide pesticides
What are 3 examples of strategies for reducing ozone-depleting substances by regulating and reducing the pollutants at the point of emission?
- recover and recycle CFCs from refrigerators and AC units
- legislate to have fridges returned to the manufacturer and coolants removed and stored
- capture CFCs from scrap car air conditioner units
What is an example of a strategy for reducing ozone-depleting substances by cleaning up and restoration?
add ozone to or remove chlorine from stratosphere
When was the Montreal Protocol created?
1987
Chlorine atoms react with ozone, which results in ozone destruction; they can also react with oxygen atoms, preventing ozone formation. In both of these processes, the chlorine atoms are formed back again and are able to react with ozone or oxygen atoms. What is this phenomena an example of?
a chain reaction with positive feedback
How many people are exposed to outdoor air pollution per year?
1 billion
How many people die prematurely due to air pollution each year?
1 million
What percent of GPD is lost by air pollution in MEDCs?
2%
What percent of GPD is lost by air pollution in LEDCs?
5%
What percent of urban air pollution in LEDCs comes from old motor vehicles which are poorly maintained?
over 90%
primary pollutants
emitted directly from a process
secondary pollutants
formed when primary pollutants undergo a variety of reactions with other chemicals already present in the atmosphere
What are 3 examples of secondary pollutants?
- tropospheric ozone
- particulates from gases
- peroxyacetyl nitrate (PAN)
What are 3 sources of primary pollutants?
- combustion of fossil fuels
- building sites
- forest fires
What are 5 examples of primary pollutants?
- carbon monoxide (CO)
- carbon dioxide (CO2)
- nitrogen oxides (NOX)
- sulfur dioxide (SO2)
- particulates (PM)
What percent of the total ozone is in the troposphere?
about 10%
What concentrations is the ozone in the troposphere?
0.02-0.3 ppm
What pollutants emitted during the combustion of fossil fuels aid in the formation of tropospheric ozone?
nitric oxide (NO) and hydrocarbons (VOCs)
How is nitric oxide formed during combustion?
nitric oxide is formed from nitrogen and oxygen in the air during combustion due to high temperatures
How are hydrocarbons formed during combustion?
hydrocarbons are formed due to the incomplete combustion of fuels
How is ozone formed in the troposphere?
Nitric oxide (NO) reacts with oxygen to form nitrogen dioxide (NO2), which forms a brown gas/haze (hydrocarbons/carbon monoxide accelerate the formation of NO2) → when nitrogen dioxide absorbs sunlight it breaks apart into NO and oxygen atoms → the oxygen atoms react with oxygen molecules (O2), forming ozone (O3)
What are 5 effects of ozone?
- oxidizing agent
- degrades chlorophyll
- decreases lung action
- eye, nose, and throat irritant
- attacks rubber, cellulose, and some plastics
How is particulate matter formed?
burning almost any organic material releases small articles of carbon and other substances
What are the 3 dangers of particulates?
- enter our bodies when our respiratory filters (nose and hairs lining the passages of the bronchi and lungs) cannot catch the particulates
- many particulates are carcinogenic (cancer-causing)
- crops can become covered with particulates reducing their productivity
In what conditions is it common for photochemical smog to form?
warm and sunny days (it can also be caused by fires)
What is photochemical smog mainly a combination of?
NO2 and ozone (truly a combination of around 100 different primary and secondary pollutants)
Why is photochemical smog at its maximum in the early afternoon?
the smog-causing reaction is a photochemical reaction, so it reaches its peak in the afternoon sun
How is photochemical smog formed?
photochemical smog is formed when NOX and VOCs react with sunlight to create ozone
Where is smog often found?
smog is often found in large cities that are low lying or surrounded by mountains which limits atmospheric mixing (blocks wind)
How does thermal inversion make things worse?
normally air over the cities is relatively warm and rises, which disperse the pollution from the ground level (warm air → cool air → cooler air); but on hot days (inversion), warmer air from the surrounding areas can move in over the city, which acts as a cap, trapping pollution (cool air → warmer inversion layer →cool air)
What are 3 examples of strategies for reducing smog by altering the human activity producing pollution?
- consume less, burn less fossil fuel
- act as informed consumers for purchase of energy efficient technologies
- lobby governments increase renewable energy use
What are 3 examples of strategies for smog by regulating and reducing the pollutants at the point of emission?
- government regulation/taxation
- catalytic converters to clean exhaust of primary pollutants from car exhaust
- fuel quality may be regulated by government
What is an example of a strategy for reducing smog through cleaning up and restoration?
afforestation may increase carbon sinks and filter air
What is most important in managing photochemical smog?
prevention
Which type of air pollution is usually a greater threat to human health?
indoor air pollution
According to the EPA, what are the 4 most dangerous indoor air pollutants?
- tobacco smoke
- formaldehyde
- radioactive radon-222 gass
- very small, fine, ultra fine particles
How many chemicals have been identified in secondhand tobacco smoke?
more than 7,000 chemicals
How many of the chemicals that have been identified in secondhand tobacco smoke are known to be harmful?
250
What are 3 examples of chemicals found in tobacco smoke?
- hydrogen cyanide
- CO
- ammonia
By what percent does living with a smoker increase a nonsmoker’s chances of developing lung disease?
20-30%
What are 7 examples of carcinogens (cancer-causing)?
- arsenic (found in rat poison)
- benzo-a-pyrene
- benzene
- cadmium
- chromium
- nickel
- vinyl chloride
What can household dust mites cause?
asthma attacks and allergic reactions
Where is asbestos found?
found in insulation of old homes
When was asbestos banned in the US?
1978
Where is radon-222 found?
radon-222 is found in some soils and rocks
What are 3 examples of construction materials that use formaldehyde resins?
- paneling
- particle board
- plywood
What are 3 examples of solutions to indoor air pollution?
- source control
- improved ventilation
- air cleaners
What are 2 examples of ways to solve indoor air pollution by source control?
- enclose/remove sources of asbestos
- adjust gas burning stoves, furnaces, and heaters to reduce emissions
What is the most effective approach to reducing indoor air pollution?
source control
What are 2 examples of ways to solve indoor air pollution by improving ventilation?
- open windows and doors
- operate fans to draw outside air
What are 2 factors to consider when installing air cleaners?
- how well it collects particles and pollutants
- the rate at which it pulls air through
acid deposition
acid coming down from the air
dry acid deposition
acid comes down as ash/dry particles
wet acid deposition
acid comes down as rain/snow
acids
chemicals that can give H+ ions away
What is the natural pH of rain?
5.6
What are the 3 main primary pollutants that lead to acid deposition?
- sulfur dioxide (SO2)
- nitrogen oxides (NO and NO2)
- carbon dioxide (CO2)
Where does SO2 mainly come from?
mostly from coal
Where does NO and NO2 mainly come from?
mostly from vehicles
What are 2 natural sources of pollution that lead to acid deposition?
- SO2 from volcanoes
- NOX from lightning strikes
What is the main human caused source of pollution that lead to acid deposition?
combustion of fossil fuels
What are 2 direct effects of acid deposition?
- weakening tree growth in coniferous forests
- acid falling on lakes and ponds, decreasing the pH of the water and affecting aquatic organisms
What are 2 indirect effects of acid deposition?
- toxic effects (increased solubility of metal ions such as aluminum which is toxic to fish and plant roots)
- nutrient effects (leaching of nutrients)
What are 5 examples of acid deposition effects on coniferous forests?
- leaves and buds show yellowing
- growth is reduced
- symbiotic root microbes are killed
- nutrients are leached out of soil
- releases toxic aluminum which damages root hairs (weakened trees die)
What are 5 toxic effects of acid deposition?
- aluminum ions (acid deposition decreases the pH of soil, making aluminum more soluble which allows it to end up in streams and rivers → aluminum can disturb a fish’s ability to regulate the amount of water and salt in its body)
- lichens (a symbiotic pairing of an alga and a fungus that are used as an indicator species → as the distance from the source of pollutants increases more and more species are able to survive)
- nutrient removal effect on soil fertility (acid rain affects the soil by reducing the ability of soil particles to hold on to nutrients)
- buildings (limestone will react with acid and simply dissolve)
- human health (dry deposition in the form of small particles can penetrate into house and our lungs)
What type of issue are climate change and ozone depletion?
global
Why is acid deposition a regional issue?
the pollutants return to the surface before spreading over long distances
What does dry deposition typically consist of?
sulfur dioxide, sulfur trioxide, and nitrogen oxides
What does wet deposition typically consist of?
sulfurous acid, sulfuric acid, and nitric acid
Does wet or dry deposition occur further from its initial source?
wet deposition
Which areas are most strongly affected by acid deposition?
areas downwind of major industrial centers
What are 3 examples of places strongly affected by acid deposition as a result of being downwind from a major industrial site?
- Scandinavian forests affected by Western Europe
- Canada affected by the US
- Southeast Asia affected by China
What are 3 examples of strategies for reducing acid deposition by altering human activity and producing pollution?
- replace fossil fuel use by using alternatives (for example, ethanol to run cars)
- reduce overall demand for electricity
- use low sulfur fuels, remove sulfur before burning, or burn mixed with limestone
What are 2 examples of strategies for reducing acid deposition by regulating and reducing the pollutants at the point of emission?
- clean-up technologies at “end of pipe” locations
- catalytic converters convert nitrous oxides back to nitrogen gas
What are 3 examples of strategies for reducing acid deposition thorough clean up and restoration?
- liming acidified lakes and rivers
- liming forestry plantations
- international agreements
By 1990, how many lakes were virtually lifeless?
over 400
What are 4 examples of ways we have tried to reduce the effects of acid deposition?
- liming lakes to neutralize acidity
- reducing emissions
- pre-combustion techniques
- end of pipe measures
pre-combustion techniques
remove sulfur before combustion
end of pipe measures
remove SO2 and NOX after combustion
