Do Now

Do Now

1. Get out your layers of atmosphere foldable & Layers of atmosphere hw.

2. Why does temperature increase with altitude in the thermosphere?

3. What are at least 4 ways you know when things are due in this class?

Good Ozone

• Formula: 02 + 0 = 03

• Location: Stratosphere ≈ 10 – 50 Km• Function: Absorbs harmful UV rays from the

sun.

Good Ozone

• What is the ozone layer? – Concentration of ozone found in the stratosphere

Problem With Stratospheric Ozone: Are humans Affecting Good Ozone?

• Chemicals humans produce and use break up ozone (03)

Source of the problem – Chlorofluorocarbons (CFCs)

• What are CFCs?– Chlorofluorocarbons– Anyone ever heard of “Freon”?

Source of the problem – Chlorofluorocarbons (CFCs)

• What are CFCs used for? – Coolants (air conditioning & refrigeration)– Cleaning for electrical components– Aerosol Sprays– Plastic Foams

How are CFCs destroying stratospheric ozone?

1. CFCs move to ozone layer2. Sunlight separates chemicals into atoms3. Chlorine atoms break up 03

4. Creating ClO (chlorine monoxide) & 02

5. Oxygen breaks up ClO, releasing the Cl to break up more 03

CFCs and Ozone

One Chlorine atom from CFCs has the ability to destroy THOUSANDS of ozone molecules. YIKES!!!

Result

• A decrease in ozone (03) allows more UV to reach earth’s surface

• This has caused a hole in the ozone above Antarctica

Problems with Stratospheric Ozone Depletion

• More severe sunburns• Cataracts• Increase occurrence of skin cancers• Reduces production of key crops and

phytoplankton

Montreal Protocol

• International agreement • Sponsored by the United Nations• Eliminated use and production of CFCs

Bad Ozone: Tropospheric Ozone

• Primary Contributor of smog• Made through a chemical reaction of oxides of

nitrogen (Nox) & Volatile Organic Compounds (VOCs) in the presence of the sun.

Two Primary Pollutants Required to Produce Tropospheric Ozone

Three Requirements for Tropospheric Ozone Generation

• NOx

• VOC• Sunlight

Diagram & Reactions of Ground-Level Ozone Generation

Diagram & Reactions of Ground-Level Ozone Generation