Ozone

How do we know there is a hole? We’ve been studying the ozone since Satellites and weather balloons helped with the research. In the 1980’s scientists saw a decrease in ozone and a hole had started to form. They tested and retested and checked their models and the equipment. It was true data; a hole was forming over Antarctica; the ozone was thinning.

What is the big deal? Ozone is the sunscreen around the Earth. It is a very thin layer of molecules built up in the stratosphere. (Remember the homework reading about the formation of ozone early on Earth?) Life both plants and animals avoid DNA damage from the sun’s radiation because ozone absorbs UV radiation. (Have you heard of black lights?)

Atomic Structure Forms of the gas with oxygen atoms.

What are UV rays? The sun’s rays are limited to the wavelengths falling in the area of the yellow energy line.

The bad guys.

What caused the loss of Ozone? The new class of chemicals that we created for air conditioning and cooling refrigerator and freezers was a major problem. You may have heard of CFC’s or freon that was used in car air conditioners. We have to get them replaced occasionally. With the new inventions of the early 20 th Century we had atmospheric problems.

How did these chemicals get into the air? Refrigerants…air conditioners Aerosol cans Making styrofoam Industrial cleaners Go to to see a video applet of what these CFC’s do to ozone.

The bad guys at work.

90% of Ozone is in the Stratosphere 3 ozone molecules: 2 MILLION OXYGEN MOLECULES: 8 MILLION NITROGEN MOLECULES O O 2 2, 000, N 2 8, 000,000

s/ozone_concentration_graph.gif 90

OZONE ABSORPTION

Good Ozone Problems NoaaNoaa NOAA

OZONE HISTORY

Anvil Cloud is bumping the stratosphere. g

What are the effects of ozone depletion? Less Ozone means more UV radiation. Sunburns increase. Skin cancer increases. Cataracts increase. DNA damage to animal and plants. Types of algae in the ocean may be damaged. Weakened immune systems/