1. 1 Ozone good & bad

2. 2 Ozone (parts per million) 0 20 40 60 80 100 Altitude (km) Troposphere Mesosphere Thermosphere Ozone In the Atmosphere Altitude (miles) 10 0 20 30 40 50 60 90% of ozone is in the stratosphere 02468 10% of ozone is in the troposphere

3. 3 UVc - 100% Absorption UVb - 90% Absorption UVa - 50% Absorption & Scattering Ozone is the Earths natural sunscreen Ozone (parts per million) 0 20 40 60 80 100 Altitude (km) Troposphere Mesosphere Thermosphere Altitude (miles) 10 0 20 30 40 50 60 02468

4. 4 Chemicals that Destroy Stratospheric Ozone Cl is much more abundant than Br Br is about 50 times more effective at O 3 destruction From Ozone FAQ - see http://www.unep.org/ozone/faq.shtml

5. 5 October Average Ozone Hole Low Ozone High Ozone

6. NO x NMVOCs NO x NMVOCs CONTINENT 2 OCEAN O3O3 Boundary layer (0-2.5 km) Free Troposphere CONTINENT 1 Tropospheric ozone links air pollution & climate change (1) primary constituent of smog in surface air [NRC, 1991] (2) 3 rd most important greenhouse gas [IPCC, 2001] OH HO 2 VOC, CH 4, CO NO NO 2 h O3O3 O3O3 Hemispheric Pollution Direct Intercontinental Transport greenhouse gas air pollution (smog)