The Ozone Layer

Name: _________________________________       Date: _____________

High up the atmosphere, a protective ozone shields us from the Sun's ultraviolet rays. In the 1980s, scientists noticed an alarming thinning of this ozone layer, especially over Antarctica. What caused this ozone "hole"? What's being done about it? You'll find out in this Planet Diary activity.

1. Start with a look at ultraviolet (UV) rays. Go to Thinning Ozone Layer: More UV Coming to Earth. Why are UV rays dangerous?
2. What stops UV rays from getting to Earth's surface?
3. Click ozone at the bottom of the page. What have scientists observed about the ozone layer?
4. How do CFCs get into the atmosphere?
5. What is the effect of CFCs on ozone?
6. What has the international community done about CFCs?
7. Click trouble at the bottom of the page. How do UV-B rays affect amphibians?
8. Take the Ozone Hole Tour. Scroll to TOMS Satellite Measurement and click the movie link to ozone levels from 1978–1992. Blue and purple show low ozone levels. Click frame by frame. How did ozone levels over Antarctica change between 1978 and 1992?