Ozone in the Troposphere

Changes in the Environment

Nain Singh

Let’s begin with definition.….• Ozone - colorless, odorless gas with 3

oxygen atoms (O3)

• Pollutant - a substance that affects air, water, or other natural resources.

• Ozone hole - a region in the atmosphere in where the ozone layer has less than normal concentration of ozone.

OxygenOzone

Composition of Atmosphere

• Nitrogen 78%• Oxygen 21%• Argon 0.93%

• Other gases traces ( O3, CO2, CFCs)

The Thin Blue Veil of the Earth’s Atmosphere

The thin blue veil that shields the atmosphere.

What is the difference between

Troposphere & Stratosphere?

Troposphere vs. Stratosphere

Troposphere is the layer in

the atmosphere from the

earth’s surface to a height

of 10 miles above

Stratosphere extends

from the top of

troposphere to 100 mi

Where is ozone found?

Stratosphere

(15-21mi

)

Troposphere

(0-10mi )

10-30ppb

1000xppb

Primary pollutants emitted:

• Nitrogen Oxides (NOX)

• VOC’sa

aPrecursors of ozone

• Particulate Matter• Sulfur Dioxide• Carbon Dioxide• Lead

•a

EPA- harmful to health

• NC ranked 2nd in the US

in unhealthy ozone levels

How have humans polluted the air?

Emission of hydrocarbon in the US 1983

Petrochemical38%

Electric Utilities

0%

Automobiles36%

Industrial fuel 11%

Other15% Petrochemical

Electric Utilities

Automobiles

Industrial fuel

Other

Anthropogenic Sources

It’s the CFC’s!

O3 uv O + O 2

O + O3 uv 2O2

Net Loss: 2O3 = 3O2

Ozone layer in the stratosphere protects the earth

from the sun’s UV light

In Troposphere• Bad ozone• Harmful increase

Concentration of ozone

1910 10ppb

2000 20-30ppb

In Stratosphere• Good ozone• Decrease in protective

zones

Ozone Twin Problem

Pushing the ecosystem to the brink. Where it resides, it can protect or harm life.

Ozone hole in the stratosphere

Effect of ozone on forest ecosystem

• May alter sensitive plant species in forests• Reduces nutrient levels• Changes mortality rates of plant species• Other ecological impacts not known?

Research on ozone effects on forest trees

Plays a role in the decline of• Ponderosa pine in California• Red spruce in N. Appalachians• Pitch pine in New Jersey• Yellow pine in Southern US

Recent Developments...

• Montreal Protocol Amended in 1990 signed by 36 nations called for a phasing out of CFCs, halons, and other forms of precursors by the year 2000.

Recent Developments...

Amendments to the Clean Air Act in 1990

-EPA is responsible for setting guidelines

-Catalytic converter in vehicles to reduce pollution

-Use of devices in factories, power plants, homes

-Reduce use of plastics and CFC’s products

Clean Air Act Amendments

1990

Recent Developments

Environmental problems are now more diverse and on a larger scale than ever

before experienced

NC awareness & ozone action days?

Provide information on air pollution, its causes and effects

CodePurple

Unhealthy

Code Orange

Approaching

unhealthy

Ozone pollution in North Carolina• 22 of the 23 counties monitored violate the

state ozone pollution standard• Last June Charlotte recorded dirtiest air in

U.S.• Greatest impact on children with asthma • Coal burning power plants- largest single

source

Concept mapUV

radiationAtmosphereOxygenOzoneStratosphereozone layerOzone holeSkin cancerPlant damageTroposphereCFC’sNitrogen oxidesVOC’sSmog

Summary of ozone concepts

• Ozone is a molecule of three oxygen atoms• Ozone is broken apart by the sun’s UV radiation• Ozone is destroyed by catalytic processes e.x. Cl,

NOx, Br or hydrogen

• The ozone hole is a result of man’s activities• International agreements regulated the use of CFCs

& other pollutants• The harmful effects of ozone on the ecosystem

Student: Teacher, every time I drink coffee I get a stab in my left eye

Teacher: Take the spoon out of the cup.

KEY

Condition

Changing Capacity

Environmental Scorecard

Our ideals, laws and customsshould be based on the propositionthat each generation in turn becomesthe custodian rather than the absolute owner of our resources… and eachgeneration has the obligation to pass this inheritance on to the future

-Alden Whitman

For making an impact

Who Moved My Cheese?

“Things that matter most must never be at the mercy of things that matter least.” Goethe