1. Chapter 17: Atmospheric Science and Air Pollution

2. Atmosphere surrounds earth consists of N2, O2, Ar and others
today's altering molecules
consist of CH4, O3, CO2
made up of layers
ozone layer

3. Other Atmospheric Properties
atmospheric pressure
force per unit of area that air exerts on the surface of Earth
declines with altitude
atmospheric humidity
ratio of water vapor contained in a given volume of air in relation to it's maximum amount possible
the more humidity the hotter it seems

4. Seasons determined by the positioning in relation to the sun
atmosphere absorbs 70% of the energy
the shorter the distance, the more intense the sun rays
solar radiation intensity is lower at the poles and higher at the equator
tilting of the planet causes the seasons to occur

5. Air Circulation known as convective circulation
caused by differences in
humidity and temperature
warm air rises as it is less dense
cold air descends becoming denser

6. Weather & Climate
Weather specifies atmospheric conditions over short periods of time and related to relatively small areas
Climate describes patterns of atmospheric conditions across large regions and over long periods of time

7. Weather depends on the fronts affected by the pressure systems
cold→ thunderstorms
warm→ light rain
affected by the pressure
systems
high→ fair to dry weather
low→ results in clouds and precipitation

8. Thermal Inversion cooler air appears under warmer air
prevents normal convective circulation to occur
pollution is trapped under the inversion layer creating health problems like asthma
killer smog in London
asthma in San Joaquin valley

9. Global Climate Patterns
Hadley cells: between equator and 30º
heavy rain at the equator
arid at 30º

10. Global Climate Patterns
Ferrer cells and polar cells lift air creating rain at ~60º

11. Wind Patterns
caused by the interaction of Hadley and Ferrer cells and Earth's rotation
Coriolis effect: winds are curved

12. Outdoor Air Pollution air pollutants natural sources
human made sources

13. Natural Pollutants we have no control, occur naturally
volcano eruptions
Mt. Pinatubo
produces particles
circle the globe and
remain in suspension
for months
acid rain
affect temperature

14. Natural Pollutants dust storms Dallas dust storm 2007
Texas dust storm 1930's

15. Natural Pollutants Fires soot and gases fuel buildup slash-and-burn
in tropics
El Niño
2000 TX LA T
Gulf Coast

16. Human Created Outdoor Pollution
primary pollutants
emitted directly to the troposphere
can be harmful to the environment
can form chemicals harmful to the environment
secondary pollutants
react with constituents of the atmosphere

17. Clean Air Act 1970 1990 set stricter standards for air quality
imposed limits to emissions
funds for pollution control research
1990
strengthen air quality standards
emission trading program for sulphur dioxide
other emission trading programs developed

18. EPA Standards carbon monoxide (CO) sulphur dioxide (SO2)
nitrogen dioxide (NO2)
tropospheric ozone (O3)
particulate matter
lead (Pb)

19. Carbon Monoxide colorless odorless incomplete combustion
in the U.S. 78% of it comes from vehicles
small concentrations can be lethal to most living organisms

20. Sulphur Dioxide colorless pungent odor power plants of coal
once in the atmosphere SO2 reacts forming SO3 and later forming H2SO4
H2SO4 forms acid rain

21. Nitrogen Oxides contributes to smog
NO2 is foul smelling, redish brown gas
NOx cause acid rain
product of combustion engines
vehicles produce 50% of the U.S. NOX
electricity production and industry the rest

22. Ozone product of sunlight + heat + NOX + carbon chemicals
health risk because of its instability→ O2 + Oxygen ion
oxygen ion can cause tissue damage
tissue damage can cause respiratory problems

23. Particulate Matter particles suspended in air
primary pollutants → dust and soot
secondary pollutants → sulphates and nitrates
can damage respiratory tissues
wind-blown result of human activities

24. Lead particulate matter enters food chain
can cause nervous system malfunction
present in gasoline to improve performance
industrialized nations phased out leaded gasoline
industrial metal smelting is the problem now

25. VOCs volatile organic compounds hydrocarbons
methane forms part of natural gas
propane used as portable fuel
butane used in portable lighters
octane component of gasoline

26. Pollutants in the U.S.
2006
137 trillion tons
EPA data

27. Pollution Decreased since 1970
emissions declined 53% since 1970
cleaner burning vehicles
catalytic converter
clean coal technology
baghouse filters
electrostatic precipitators
scrubbers
phase-out of lead in gasoline

28. Toxic Pollutants
188 toxic pollutants identified by the Clean Air Act in 1990
effects on people
cancer
reproductive defects
neurological problems
developmental problems
affect the immune system
respiratory diseases

29. Policy: Bush Administration
elimination of new source review of 1977
new pollution targets
retrofitting aging plants with new technologies
industry protested: too costly
Bush Administration exempted older plants
allowed installing only "the best available" technology IF they ever upgraded the plant
Clear Skies (stopped by the Senate in 2005)
from command-and-control to a market-based cap-and-trade

30. Smog
fogs polluted by smoke= smog
industrial smog
photochemical smog

31. Industrial smog gray-air smog coal or oil burning CO, CO2, soot
London 1952
gray-air smog
coal or oil burning
CO, CO2, soot
mercury and sulfur in the carbon sample
sulfur reacts forming SO2
sulphuric acid
ammonium sulphate
Problems today: China, India, Eastern Europe

32. Photochemical smog requires light brown-air smog
ozone
NOx
VOCs
irritates eyes, nose, throat
car inspections
reduction of vehicles driven per day
allow certain cars to drive certain days of the week
promote mass transit
Houston 2000

33. Problems at Rural Areas
airborne pesticides
industrial pollutants from cities, factories and power plants migrate
methane from cattle (18%)
feedlots
CH4, dust, NH4, SOx
can cause respiratory problems

34. Industrialization is worsen air quality
China
Industrialization
is worsen air quality
caused by factories and power plants
emissions are released with little effort to control pollution
China & India have 58% of premature deaths worldwide (WHO)
Asian brown cloud
reduces sunlight
decreases productivity

35. Synthetic Chemicals CFCs (chlorofluorocarbons) affects the ozone layer
creating the ozone hole in Antarctica
increases UV radiation
leads to more skin cancer
ecological effects still unknown
hole in the arctic
Arctic hole

36. Montreal Protocol of 1987 addressed ozone depletion
180 nations agreed to cut CFCs production in half
production and use has dropped by 95%
alternative chemicals
CFCs take very long to brake down

37. Acid Deposition originates with the NOx and SOx
forms of precipitation known as acid rain
rain, snow, sleet and hail
fog
dry particles
originates with the NOx and SOx
pollutants react with water, O2, oxidants
produce compounds of low pH (acids)
these are suspended in the troposphere before falling as rain
can cause political bickering

38. Acid Rain alters soil composition leaches chemicals from the soil
harming plants and soil organisms
also mobilizes toxic chemicals
converts them to soluble forms
affects agriculture
affect lakes and rivers
causing high mortality in fishes and amphibians

39. Acid Rain erosion of buildings corrodes cars
erosion of statues and obelisks
has not been reduced as expected in 1990
more reduction of sulphur oxides and nitrogen oxides need to occur

40. Indoor Air Pollution
higher concentration of pollutants indoor than outdoor
workplaces, schools, homes
volatile chemicals in the air
insecticides
cleaning fluids
plastics
chemically treated wood

41. Other Sources
wood burning
chimneys
cooking
tobacco smoking
radon

42. Indoor VOC Pollution perfumes paints plastics oils/candles
cleaning fluids
adhesives (glues)
pesticides and insecticides
ink (fax, photocopiers, printers)
color films

43. Living Organisms also Pollute
dust mites
animal dander
mold
bacteria
THE END