Ozone

http://www.dnr.state.wi.us/Org/caer/ce/eek/earth/air/ozonlayr.htm

How do we know there is a hole?

• We’ve been studying the ozone since 1970. 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 http://www.ucar.edu/learn/1_5_1.htm

• Forms of the gas with oxygen atoms.

What are UV rays? http://www.ucar.edu/learn/1_5_1.htm

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 20th Century we had atmospheric problems.

How did these chemicals get into the air?

• Refrigerants…air conditioners• Aerosol cans• Making styrofoam • Industrial cleaners

• Go to http://www.ucar.edu/learn/1_6_1.htm 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

• O3 3

--------

• O2 2, 000,000

--------• N2 8, 000,000

http://ozonewatch.gsfc.nasa.gov/facts/images/ozone_concentration_graph.gif

90

OZONE ABSORPTION

Good Ozone Problems

Noaa

NOAA http://www.ozonelayer.noaa.gov/science/StratO3.jpeg

OZONE HISTORY• http://ozonewatch.gsfc.nasa.gov/facts/images/halley_toms_ozone.png

http://www.weatherquestions.com/What_is_the_ozone_layer.htm

Anvil Cloud is bumping the stratosphere.

http://www.weatherquestions.com/anvil2.jpg

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/