1. mesosphere
stratosphere
troposphere

2. What is Ozone? Chemical Formula is O3
Found in the Stratosphere (good) and Troposphere (bad).
Stratosphere ozone protects Earth from the Sun’s ultraviolet radiation.

3. Where is ?

4. Electromagnetic Spectrum
BACK

5. The Hole in the Ozone layer
Area over South Pole where ozone (O3) loss (called “depletion”) exceeds 50 %
Happens every Sept., Oct. Nov. since 1980s

6. Dobson Units
The Dobson unit measures Ozone thickness at standard temperature
and pressure.

8. Jan. Feb. March April May June
July Aug Sept Oct Nov Dec.

11. The destructive chemistry:
You do not need to write this down.
CCl2 F2 + light ---> Cl + CClF2
Cl + O > ClO O2
ClO O ---> Cl + O2
Rowland and Molina
1974 paper
Nobel Prize 1995

12. Uses of CFCs. Refrigerators, freezers: 15 % (FREON)
Air conditioners in cars and homes: 20 %
Aerosols: 15 %
Foams: 24 %

14. Next
Rowland and Molina