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Air PollutionBeijing,chinaJanuary2013

Why we care:

Smog, acid rain, health hazards, global climate change

1. What is air pollution?2. Where does pollution come from?3.Air hazard events and pollution meteorology4.Air pollution and climate change5. The Ozone Hole

Todays Lecture: Air Pollution

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Pollution Meteorology

Meteorological conditions can make thepollution issue better or worse

The solution to pollution is dilution Meteorological conditions that inhibit the

dispersion of air pollution will create apollution problem

Air hazard events and pollution meteorology

Topography

At night, cold, dense surface air drainsdownhill into low-lying areas, making them

susceptible to strong temperature

inversions

Hills and mountains can trap air Sea breezes can provide cold air masses

Air hazard events and pollution meteorology

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Inversions inhibit vertical convection, trapping pollutants close

to the surface. Strong, persistent, inversions over urban areas

lead to much greater concentrations of pollutants.

Inversions

5 C warmer

Air hazard events and pollution meteorology

Los Angeles smog

29 January 2004.

The top of the

inversion layer is

easily seen against

hills

a thick brown or

slightly orange haze

-inversion is belowthe top of the highest

buildings.

--The exhaust frommore than a million

cars driven in the

morning rush hour istrapped below this

level.

Air hazard events and pollution meteorology

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Air hazard events and pollution meteorology

Air hazard events and pollution meteorology

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Jan14,2013

Other Meteorological Factors

Sunlight/clear skies increases production of

photochemical smog

Air hazard events and pollution meteorology

Rain will scrub the atmosphere because

many of the pollutants are condensation

nuclei or dissolve easily in water

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Air hazard events and pollution meteorology

CloudSeeding

Air hazard events and pollution meteorology

Chinausedcloudseeding

inBeijingjustbeforethe

2008OlympicGamesin

ordertocleartheairof

polluon.

CloudSeeding

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InFebruary2009,Chinaalso

blastediodidescksover

Beijingtoarficiallyinduce

snowfallaQerfourmonthsof

drought,andblastediodide

scksoverotherareasof

northernChinatoincrease

snowfall.Thesnowfallin

Beijinglastedforapproximately

threedaysandledtothe

closureof12mainroads

aroundBeijing

CloudSeeding

1. What is air pollution?2. Where does pollution come from?3.Air hazard events and pollution meteorology4.Air pollution and climate change5. The Ozone Hole

Todays Lecture: Air Pollution

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Air pollution and climate change

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RadiaveBudgetofAerosols

Air pollution and climate change

Mainpoint:MostaerosolsCOOLthesurfacetemperature!

Air pollution and climate change

Anyrolein

global

warming?

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Air pollution and climate change

Anyrolein

global

warming?

VanillicAcid

Sourcesofblackcarbon

(soot)?

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Air pollution and climate change

Anyrolein

global

warming?

GlobalDimming

Air pollution and climate change

Conceptthathumanaerosolscooledtheclimate,andhelptooffsetglobalwarming.

Thedecreaseofglobaldimmingagentspromoteswarming.

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1. What is air pollution?2. Where does pollution come from?3.Air hazard events and pollution meteorology4.Air pollution and climate change5. The Ozone Hole

Todays Lecture: Air Pollution

Darkestblueareas

representregionsof

maximumozone

depleon

1979

19821984 1986

1988 1990

19921994

1997

1999

2004

The Ozone Hole

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What is the ozone hole?

Media confuses it with global warming Over the poles (especially Antarctica),

stratospheric ozone depleted over past 30years

Hole presently size Antarctica Ozone (O3) contributes to the greenhouse

effect

And of course O3 creation at the ground levelis bad bad bad.

The Ozone Hole

OzoneintheAtmosphere

The Ozone Hole

90%in

Stratosphere

10%in

Troposphere

recall:

goodup

high,bad

nearby

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How is ozone formed?

UVradiaonstrikestheO2moleculeandsplitsit,

atomicoxygenassociatesitselfwithanotherO2

moleculetomakeOzone(O3)

O2+sunlight>O+O

O+O2>O3

The Ozone Hole

The Ozone Hole

Sunburn

DNAdamage(cancer)

NoDamage

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Why do we like Ozone?

Too much UV:

Eye damage, cataracts,Skin cancers

photoagingDamage to land species

Damage to aquaticspecies (plankton)

The Ozone Hole

Short answer: it protects us fromUV radiation!

What causes the depletion?

Release of man-made chemicals- CFCs (Chlorofluorocarbons) - refrigerants,aerosol sprays, solvents and foam-blowing agents

- halogen compounds (F, Cl, Br) - Fire fightersused bromine-containing halogens to put out fires

- Nox

The Ozone Hole

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The Ozone Hole

Sources that harm ozone layerThe Ozone Hole

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One chlorine atom on average - destroys one thousand ozonemolecules before converted into form harmless to ozone

The Ozone Hole

The Ozone Hole

Why over the poles?

Isolatedair

Chemical

breakdownis

favoredincold

airandbypolar

stratosphericclouds

Ozonehole

changesseasonally

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Arctic ozone hole?

2004

Antarctic ozone hole?

The Ozone Hole

Why over the poles?

2000

What does this look like on population

density map?

The Ozone Hole

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October Antarctic Ozone

Ozoneisnolongerdecreasing(1ststepintherecoveryprocess)

The Ozone Hole

TheFuture?

The Ozone Hole