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:
• O3
2 MILLION OXYGEN
MOLECULES:
• O2
8 MILLION NITROGEN
MOLECULES
• N2
3
-------2, 000,000
-------8, 000,000
http://ozonewatch.gsfc.nasa.gov/facts/image
s/ozone_concentration_graph.gif
OZONE ABSORPTION
Good Ozone Problems
NOAA http://www.ozonelayer.noaa.gov/science/StratO3.jpeg
N
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.
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/