Topic Guide:  Ozone Depletion

 

In this activity you will form groups, conduct research into Stratospheric Ozone Depletion, and report back to your lab section in the form of a presentation. At the end of this activity you will find suggestions for the format of the presentation. You will use the data you investigate as evidence for your statements. Please use these suggestions and the “How to make a class presentation” (Resource 1) as guidelines for your presentation.

 

Overview:

The sun emits short wavelength radiation (ultra-violet) that is very damaging to life. Atmospheric ozone filters most of it out so that it never reaches us at the surface. Research shows that ultra-violet radiation increases skin cancer, cataracts, and decreases phytoplankton production in the ocean.

 

Resources:

 

After completing this investigation you should be able to:

1. Understand the ozone formation processes
2. Explain ozone's importance
3. Understand the effects that people have had on the concentration of ozone in the stratosphere

 

You can go straight into exploring the data, but if you need more background information about ozone and ozone depletion, please review the websites that provide background information (found after the data section).

 

Background:

http://www.epa.gov/ozone/science/hole/whyant.html

Why is the ozone hole located over the Antarctic?

 

Ozone Data:

http://www.epa.gov/ozone/science/hole/

http://www.cmdl.noaa.gov/info/ozone_anim.html

During what season is the ozone concentration at a minimum in the Southern Hemisphere?

 

What causes this minimum?

 

Why do the contours for the distribution of ozone over Antarctica vary as much as they do on a daily basis?

 

http://jwocky.gsfc.nasa.gov/multi/buv-toms.gif

http://jwocky.gsfc.nasa.gov/multi/oz_hole_area.jpg

How has the average size of the ozone hole changed over the last 20 years?

 

http://www.cpc.ncep.noaa.gov/products/stratosphere/sbuv2to/ozone_hole.html

Here is another web site with data concerning the size of the ozone hole for the last 10 years. What does this graph tell us? Does this data differ from the previous site? If so, how could this occur?

 

 

 

 

 

 

More Background information:

Please take some time to learn more about the background information available for the topic of ozone and ozone depletion. If you learn something new and interesting, please share it with the lab in your presentation.

 

http://www.atm.ch.cam.ac.uk/tour/

http://www.ncsa.uiuc.edu/SDG/DigitalGallery/NOV_OZ.html

http://www.al.noaa.gov/WWWHD/pubdocs/Assessment98.html

http://search.eurekalert.org/e3/query.html?col=ev3rel&qc=ev3rel&qt=ozone&x=19&y=1

http://science.nasa.gov/headlines/y2000/ast12dec_1.htm?list80134

http://www.cpc.ncep.noaa.gov/products/stratosphere/sbuv2to/ozone_hole.html

 

 

Presentation Framework

Your presentation should include a brief overview explaining the significance of ozone and how studies of ozone depletion relate to issues of today. You should then choose as many of the following topics as is necessary to explain the concept. Choose topics that you think might be relevant to understanding climate change. Your presentation should include interesting findings from your investigations, backed up with data. You must use the physical data in your presentation.

 

You may choose from the following list of topics, or investigate a topic of your own. The topics in the list are examples of investigations that could be made using the data available at the URL’s listed above.

 

Data driven topics : 

• What is the general trend in the concentration of stratospheric ozone over Antarctica for the last 20 years?
• Describe the seasonal variation in ozone concentration in the Southern Hemisphere.
• What causes the contours of the distribution of ozone over Antarctica to vary on a daily basis?

 

Overview type topics:

• Why is the ozone hole located over the Antarctic?
• Where is ozone found in the atmosphere?
• Why is there a seasonal minimum?
• How can the reduction of stratospheric ozone effect the biosphere?
• What are the processes that create ozone?
• What are the processes that destroy ozone?
• How are stratospheric ozone concentrations measured?
• Why isn’t there a hole in the ozone layer over the United States?
• Why is the ozone hole more pronounced over Antarctica than the Arctic?
• What is the role of CFCs in the destruction of ozone?
• What is the global concentration of CFCs?
• How long do CFCs last in the stratosphere?
• Why are high concentrations of CFCs found in the atmosphere over the Antarctic?