1. The Ozone Hole Tejas Patel PEP Universität Bremen

2. Contents History of Ozone Loss Chemical processes in Ozone depletion Regions of Interest Polar Vortex Ozone hole only at poles??? Anthropogenic Impacts on Ozone hole Health Consequences Summary Referances

3. History of Ozone Loss Loss of ozone in the lower stratosphere over Antarctica was first noticed in the 1970s by British Antarctic Survey (BAS).

4. Vertical profile of ozone

5. Chemical processes in Ozone depletion Chlorine, bromine – from human activities Chlorine carriers – hydrochloric acid, chlorine nitrate Other compounds – nitric acid, dinitrogen pent oxide PSC Denoxification – slows removal ClO

6. Regions of Interest Ref:http://www.solcomhouse.com/akjrctic.gif

7. The Antarctic polar vortex

8. Vortex explanation Antarctic stratosphere cools descends closer to the surface Coriolis effect - sets up strong westerly circulation temperatures - lower stratosphere cool < -80C  PCS’s

9. Ozone loss over Antarctica Mostly in the lower stratosphere persists two months nearly all the ozone is depleted area the size of Antarctica most pronounced in spring/October

10. Monthly averages for October Ref:http://www.atm.ch.cam.ac.uk/tour/tour_images/oct_ozone.gif

11. Is the ozone loss only in Antarctica? Arctic – ‘low ozone event’ Arctic atmosphere, as result of the eruption of Mt Pinatubo European ozone hole - heavily populated northern mid-latitudes (30-60N) – formation smaller, much slower

12. Why is the loss more dramatic at the poles? • Polar vortex – winter polar night • Polar stratospheric clouds (-80C) • nitric acid trihydrate • Chemical reactions • occur on surface PSC’s • Occur very fast

13. What do these clouds look like? http://www.abc.net.au/science/news/img/environment/nacreous020806.jpg

14. One chlorine atom destroys one thousand ozone molecules Impact of CFC’s

15. Health Consequences • Skin cancers, sunburn, eye damage • estimated 10 % reduction ozone layer  25 % increase non-melanoma skin cancer -temperate latitudes by 2050 • Suppress immune system • DNA mutation of existing disease bacteria and viruses

16. Summary • Massive Ozone loss is in spring time in Antartic stratosphere due to anthropogenic halogens. • Difference between Artic and Antartic stratosphere is temperature. • Most of the features of polar ozone depletion is now understood but still number of issues remain to be unsolved.

17. A Little Spaß with Science

18. Thank You for being patient !!!! Questions??? Comments!!!!!! Suggestions………………

19. References • Ref:http://www.solcomhouse.com/akjrctic.gif • Ref:http://www.atm.ch.cam.ac.uk/tour/tour_images/oct_ozone.gif • www.atm.ch.cam.ac.uk/tour • http://ozonewatch.gsfc.nasa.gov/facts/hole.html • http://www.theozonehole.com/