Ozone Layer & UV Radiation – AP Environmental Science | ShowMeClass

O₃

Ozone Layer & UV Radiation

AP Environmental Science · Unit 7: Atmosphere

Learning Objectives

Describe formation & destruction of ozone

Explain how CFCs deplete ozone

Relate ozone thickness to UV penetration

Analyze effects of Montreal Protocol

Ozone Chemistry

Formation:
O₂ + UV → 2O
O + O₂ → O₃

CFC Destruction:
CFCl₃ + UV → Cl + CFCl₂
Cl + O₃ → ClO + O₂
ClO + O → Cl + O₂
1 Cl atom destroys ~100,000 O₃

UV Types

UV-C (100-280nm): Blocked by O₂ & O₃
UV-B (280-315nm): Mostly blocked by O₃
UV-A (315-400nm): Reaches surface

More CFC = less O₃ = more UV-B reaches surface

Colors

Ozone layer (O₃)

UV radiation

CFC molecules

Ozone thickness (DU)

OzoneUVCFCsMontreal

Year:1980

O₃:300 DU

UV-B:-

CFC:-

OZONE THICKNESS & CFC CONCENTRATION OVER TIME

Year 1980

CFC Emissions (kt/yr) 800

Natural O₃ Production 1.0x

Scenario

Display

Ozone Analysis

Quick Quiz▼

1. CFCs deplete ozone by releasing:

Fluorine atoms Chlorine atoms Carbon atoms Oxygen atoms

2. The ozone layer is primarily in the:

Troposphere Stratosphere Mesosphere Thermosphere

3. The Montreal Protocol (1987) banned:

CO2 emissions CFC production Methane emissions Nuclear testing