Activity #1:
Ozone Comparison, October 1979 vs. October 2000

In this activity, you can view the Earth from the unique perspective of outer space. You will examine monthly snapshots (or global datasets) of our planet’s surface and atmosphere. During this activity, you will investigate the Earth’s stratospheric ozone levels by looking for patterns and changes over time. You will make connections to global environmental issues.

Background:
Ozone gas in the stratosphere (upper atmosphere) absorbs ultraviolet light, thus protecting living things from the sun’s harmful ultraviolet radiation. Man-made chemicals and weather conditions over Antarctica combine to deplete stratospheric ozone concentrations during the winter months there. (Data from Total Ozone Mapping Spectrometer [TOMS] project).

Questions:

1. From Oct 79 to Oct 00, is there a pattern of ozone levels according to region?
    
    
2. What changes in ozone levels do you see over time? Pick at least two regions, and then compare and contrast.
    
    
3. What might be causing these changes in the ozone level?
    
    

Extension Links:

1. Ozone (http://Earthobservatory.nasa.gov/Library/Ozone/)
    
2. TOMS Project (http://toms.gsfc.nasa.gov/)
    
3. On the Trail of the Missing Ozone (http://www.epa.gov/kids/missing.htm)
    

next activity (#2): Comparing surface temperatures in January 1990 to temperatures in June 1990
previous activity (#12): Comparing UV radiation exposure to ozone during the month of October 2000