1. Ozone A PLANETARY CONTEXT Presented by Stephen Schneider Deborah Carlisle

2. Interpolating Color Data User CommentsAverage Red Average Green Average Blue exercising70.365.15.1 resting47.258.115.8 0% CO222.547.939.8 1% CO235.655.223.4 10% CO274.762.90.8 50% CO281.768.10.8 0% 1% 10% 50% You can interpolate graphically or mathematically. Having calibrated samples close to the right color will improve your accuracy. 0% CO 2 resting exercising 1% CO 2 10% CO 2 50% CO 2 Rest % = 1% + × (10% – 1%) = 1% + 0.299 × 9% = 3.7% 47.2 – 35.6 74.7 – 35.6

3. Atmospheric Absorption The Earth’s atmosphere absorbs most wavelengths of the radiation incident on it from space This is a good thing for life – high energy photons would sterilize the planet! It’s an intriguing coincidence(?) that our eyes work at wavelengths where the atmosphere is transparent.

4. Why Space-based Observatories?

5. Atmospheric Heating Stratosphere Oxygen (O 2 ) is split apart by solar ultraviolet light, and O atoms recombine to make ozone (O 3 ). O 2 and O 3 both absorb ultraviolet light, heating this layer. Troposphere Sunlight heats surface. Atmosphere absorbs heat from surface.

6. 6 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

7. 7 UVc - 100% Absorption UVb - 90% Absorption UVa - 50% Absorption & Scattering Ozone is the Earth’s 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

8. Earth’s Energy Budget

9. 9 October Average Ozone Hole Low Ozone High Ozone

10. 10 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

11. Ground-level Ozone Ozone problems are caused by pollutants, not greenhouse gases. At ground level, the presence of NO x and volatile organics stimulates production of this caustic chemical. Ozone can cause lung damage and exacerbate breathing problems.