1. Nov. 3, 2008 1 Jan. 10, 2003 - local noon, Kiruna, Sweden

2. Nov. 3, 2008 2 Jan. 14, 2003 Southern Norway

3. Nov. 3, 2008 3 Polar Stratospheric Ozone Dr. Paul A. Newman http://code613-3.gsfc.nasa.gov/People/Newman/ NASA’s Goddard Space Flight Center IPY Webcast NASA GSFC Nov. 3, 2008 Dr. Paul A. Newman http://code613-3.gsfc.nasa.gov/People/Newman/ NASA’s Goddard Space Flight Center IPY Webcast NASA GSFC Nov. 3, 2008

4. 4 Ozone Basic Facts O 3 = Ozone is composed of 3 oxygen atoms. O 3 concentrations are small (peak concentrations are about 10 parts per million at an altitude of about 32 km (20 miles). O 3 absorbs harmful solar ultraviolet radiation. A necessary condition for life. O 3 is mainly found in the the stratosphere. O 3 at the ground is a problem! Inhalation of ozone for very small concentrations can cause lung problems. Mass: (Billion Metric Tons) Sun1,9900,000,000,000,000,000 Earth5,980,000,000,000 Global atmosphere5,300,000 Global ozone3 Oxygen Ozone

5. Nov. 3, 2008 5 Atmospheric Composition Nitrogen78.1% Oxygen20.9% Argon0.9% Water1.4% (tropics) 0.2% (poles) 0.0004% (stratosphere) CO 2 0.0360% O 3 0.001% (stratosphere) 0.00001% (troposphere) Nitrogen78.1% Oxygen20.9% Argon0.9% Water1.4% (tropics) 0.2% (poles) 0.0004% (stratosphere) CO 2 0.0360% O 3 0.001% (stratosphere) 0.00001% (troposphere)

6. Nov. 3, 2008 6 180200220240260280300 Temperature (K) 0 20 40 60 80 100 Altitude (km) Troposphere Stratosphere Mesosphere Thermosphere Atmospheric Structure Altitude (miles) 10 0 20 30 40 50 60 81 o F45 o F9oF9oF-27 o F-63 o F-99 o F-135 o F

7. Nov. 3, 2008 7 0 20 40 60 80 100 Altitude (km) Troposphere Stratosphere Mesosphere Thermosphere Atmospheric Structure Altitude (miles) 10 0 20 30 40 50 60 Airliners fly at 30,000-40,000 feet

8. Nov. 3, 2008 8 0 20 40 60 80 100 Altitude (km) Troposphere Stratosphere Mesosphere Thermosphere Atmospheric Structure Altitude (miles) 10 0 20 30 40 50 60 ER-2 flies at 70,000 feet

9. Nov. 3, 2008 9 0 20 40 60 80 100 Altitude (km) Troposphere Stratosphere Mesosphere Thermosphere Atmospheric Structure Altitude (miles) 10 0 20 30 40 50 60 Oxygen Ozone

10. Nov. 3, 2008 10 Ozone (parts per million) 0 20 40 60 80 100 Altitude (km) Troposphere Mesosphere Thermosphere Ozone Facts Altitude (miles) 10 0 20 30 40 50 60 90% of ozone is in the stratosphere 02468

11. Nov. 3, 2008 11 Ozone (parts per million) 0 20 40 60 80 100 Altitude (km) Stratosphere Mesosphere Thermosphere Ozone Facts Altitude (miles) 10 0 20 30 40 50 60 02468 10% of ozone is in the troposphere

12. Nov. 3, 2008 12 Digression: Dobson Units 3 mm = 300 Dobson Units Total Ozone is a measure of the total column amount above us. Measured in Dobson Units If we bring all of the ozone above us down to the Earth’s surface The thickness would be about 3 millimeters (~0.1 inches) = 300 Dobson Units (approximately the global average) 100 Dobson Units = 1 millimeter in thickness Total Ozone is a measure of the total column amount above us. Measured in Dobson Units If we bring all of the ozone above us down to the Earth’s surface The thickness would be about 3 millimeters (~0.1 inches) = 300 Dobson Units (approximately the global average) 100 Dobson Units = 1 millimeter in thickness *The Dobson Unit is a convenient unit of measurement for total column ozone 2¢ 10¢

13. Nov. 3, 2008 13 Ozone (part per million) 0 20 40 60 80 100 Altitude (km) Stratosphere Ozone Facts Altitude (miles) 10 0 20 30 40 50 60 02468 UVc - 100% Absorption UVb - 90% Absorption UVa - 50% Absorption & Scattering Ozone is the Earth’s natural sunscreen

14. Nov. 3, 2008 14 UV Health Facts UV pluses: produces vitamin D in the skin - necessary to maintain levels of calcium and phosphorus (10-15 minutes twice a week) UV minuses: –Eye damage: cataracts, photokerititus (snowblinding), ocular cancers –Skin cancers: basal, squamous, melanoma –photoaging –Damage to various land speciesDamage to aquatic species –Increased pollution levels in urban environments UV pluses: produces vitamin D in the skin - necessary to maintain levels of calcium and phosphorus (10-15 minutes twice a week) UV minuses: –Eye damage: cataracts, photokerititus (snowblinding), ocular cancers –Skin cancers: basal, squamous, melanoma –photoaging –Damage to various land speciesDamage to aquatic species –Increased pollution levels in urban environments Cataract Melanoma Mexico City

15. Nov. 3, 2008 15 Large polar ozone losses result from chlorine and bromine compounds that are mainly human produced

16. Nov. 3, 2008 16 CFC-12 released in troposphere Carried into stratosphere in the tropics by slow rising circulation CFC-12 photolyzed in stratosphere by solar UV, releasing Cl Cl catalytically destroys O 3 Cl reacts with CH 4 or NO 2 to form non- reactive HCl or ClONO 2 Polar loss Chlorine Pathway

17. Nov. 3, 2008 17 Source Gases Cl is much more abundant than Br, but … Br is about 60 times more effective at O 3 destruction From Ozone FAQ - see http://www.unep.org/ozone/faq.shtml

18. Nov. 3, 2008 18 Atmospheric Chlorine Trends from NOAA/ERL - Climate Monitoring Division Updated Figure made by Dr. James Elkins from Trends of the Commonly Used Halons Below Published by Butler et al. [1998], All CFC-113 from Steve Montzka (flasks by GC/MS), and recent updates of all other gases from Geoff Dutton (in situ GC). 50 years 102 years 5 years 42 years 85 years CFC-11 CCl 4 CFC-113 CFC-12 CH 3 CCl 3

19. Nov. 3, 2008 19 Polar Stratospheric Clouds Central, Sweden January 14, 2003 - P. Newman

20. Nov. 3, 2008 20 Solomon et al. (1986), Wofsy and McElroy (1986), and Crutzen and Arnold (1986) suggest reactions on cloud particle surfaces as mechanism for activating Chlorine HCl ClONO 2 HNO 3 Cl 2 Cl 2 is easily photolyzed by UV & blue/green light HNO 3 is sequestered on PSC Antarctic ozone hole theory

21. Nov. 3, 2008 21 Polar Ozone Destruction 1. O 3 + Cl  ClO + O 2 Only visible light (blue/green) needed for photolyzing ClOOCl No oxygen atoms required Net: 2  O 3 + h  3  O 2 2 O 3 3 O 2 3. ClOOCl+h  2 Cl+O 2 2. 2 ClO + M  ClOOCl + M

22. Nov. 3, 2008 22 Antarctic Measurements Aurora over Halley Bay Station, Antarctica, 75.6ºS 26.5ºE Brunt Ice Shelf, Coats Land 105 days of continuous darkness, twice per year re-supply Population: 65 in summer, 15 in winter Aurora over Halley Bay Station, Antarctica, 75.6ºS 26.5ºE Brunt Ice Shelf, Coats Land 105 days of continuous darkness, twice per year re-supply Population: 65 in summer, 15 in winter

23. Nov. 3, 2008 23 October Antarctic Ozone pre-1985

24. Nov. 3, 2008 24 October Antarctic Ozone

25. Nov. 3, 2008 25 TOMS - August 31, 2003 Orange/Yellow indicates higher ozone levels. Blue colors indicate low ozone values Dark color over pole shows the extent of polar night, no ozone observations Antarctic ozone hole is defined as the region covered by low ozone values

26. 10/25/200826 Ozone Hole Area N. America 1 st observed SH major warming (2002) Sep. 21, 2008 Sep. 30, 2008

27. Nov. 3, 2008 27 October Average Ozone Hole

28. Nov. 3, 2008 28 March Average total ozone

29. Nov. 3, 2008 29 Arctic & Antarctic Trends

30. Nov. 3, 2008 30 What’s being done?

31. Nov. 3, 2008 31 What Can You Do? Avoid excessive solar exposure (limit sun between 11AM and 2PM). Wear and encourage others to wear sunscreen (SPF rating of 15). Even with sunscreen, prolonged exposure is not smart. Check your skin regularly. Wear sunglasses that screen UV. Hats and other coverings Make note of the UV index on the news or web: http://www.epa.gov/sunwise/uvindex.html Avoid excessive solar exposure (limit sun between 11AM and 2PM). Wear and encourage others to wear sunscreen (SPF rating of 15). Even with sunscreen, prolonged exposure is not smart. Check your skin regularly. Wear sunglasses that screen UV. Hats and other coverings Make note of the UV index on the news or web: http://www.epa.gov/sunwise/uvindex.html

32. Nov. 3, 2008 32 Atmospheric Chlorine Trends from NOAA/ERL - Climate Monitoring Division Updated Figure made by Dr. James Elkins from Trends of the Commonly Used Halons Below Published by Butler et al. [1998], All CFC-113 from Steve Montzka (flasks by GC/MS), and recent updates of all other gases from Geoff Dutton (in situ GC). 50 years 102 years 5 years 42 years 85 years CFC-11 CCl 4 CFC-113 CFC-12 CH 3 CCl 3 U. S. CFC production stopped by President George Bush in 1992 Montreal Protocol Signed (1987)

33. 10/25/200833 Antarctic EESC Obs.Projections Using WMO scenario A1-adj., we can project forward from 1980 to show recovery of EESC around 2065. Recovery of 1970 Antarctic EESC in 22 nd century!

34. Nov. 3, 2008 34 Ozone future Projected area of the ozone hole

35. Nov. 3, 2008 35 Summary Stratospheric ozone is a critical gas for screening solar UV radiation. Human produced ozone destroying substances (ODS) have caused large losses of polar ozone over both poles ODSs have been regulated under international agreements and are slowly decreasing. Ozone levels should recover within the next 50-70 years. Climate change remains a big unknown for ozone recovery Stratospheric ozone is a critical gas for screening solar UV radiation. Human produced ozone destroying substances (ODS) have caused large losses of polar ozone over both poles ODSs have been regulated under international agreements and are slowly decreasing. Ozone levels should recover within the next 50-70 years. Climate change remains a big unknown for ozone recovery