The Ozone Hole

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The Ozone Hole

• Tejas Patel
• PEP
• Universität Bremen

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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

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History of Ozone Loss

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

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Vertical profile of ozone
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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

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Regions of Interest

• Refhttp//www.solcomhouse.com/akjrctic.gif

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The Antarctic polar vortex
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Vortex explanation

• Antarctic stratosphere cools
• descends closer to the surface
• Coriolis effect - sets up strong westerly
  circulation
• temperatures - lower stratosphere cool lt -80C ?
  PCSs

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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

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Monthly averages for October
Refhttp//www.atm.ch.cam.ac.uk/tour/tour_images/o
ct_ozone.gif
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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

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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 PSCs
• Occur very fast

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What do these clouds look like?

• http//www.abc.net.au/science/news/img/environment
  /nacreous020806.jpg

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One chlorine atom destroys one thousand ozone
molecules
Impact of CFCs
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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

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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.

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A Little Spaß with Science
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Thank You for being patient !!!!

• Questions???
• Comments!!!!!!
• Suggestions

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References

• Refhttp//www.solcomhouse.com/akjrctic.gif
• Refhttp//www.atm.ch.cam.ac.uk/tour/tour_images/o
  ct_ozone.gif
• www.atm.ch.cam.ac.uk/tour
• http//ozonewatch.gsfc.nasa.gov/facts/hole.html
• http//www.theozonehole.com/