Ozone Hole Expert Groups

Objective:

Students will do research on the topics associated with the hole in the ozone layer over Antarctica.

Students will write five facts about their topics and one question for each of those facts.

Students will present what they learned to the rest of the class.

Standards Addressed: Benchmarks

Earth Science

Grades 3-5: D. Analyze weather and changes that occur over a period of time.
Grades 6-8: D. Explain that the universe is composed of vast amounts of matter, most of which is at incomprehensible distances and held together by gravitational force. Describe how the universe is studied by the use of equipment such as telescopes, probes, satellites and spacecraft.

Scientific Inquiry

Grades 3-5: C. Develop, design and safely conduct scientific investigations and communicate the results.

Procedure:

Break the students into groups of three. Each group will become an expert on the topic they select. The teacher can write the topics on 3 x 5 cards and groups can select their topic.
Students will do research on the topic. They will find five facts about their topic and then write a question for each fact.
The group will then make a presentation about their topic, teaching the five facts they thought were important.
A test could be given using the questions the students made.

Topics:

What are the layers of the earth's atmosphere?
What is ozone?
What are chloroflurocarbons (CFC's) and from where do they come?
What is global warming?
What is the ozone hole and where is it located?
What is the greenhouse effect?

Teacher Information:

What are the layers of the earth's atmosphere?
http://www.atm.ch.cam.ac.uk/tour/index.html

We live in the troposphere.
Most weather occurs here such as rain clouds.
It is 10 km (6.2 miles) deep.
The other layers are the stratosphere, the mesosphere, the thermosphere and the exosphere.
The stratosphere is the important region where the ozone hole and global warming originate.

What is Ozone?
http://www.atm.ch.cam.ac.uk/tour/index.html

Ozone forms a layer in the stratosphere.
It is thinnest in the tropics (around the equator) and denser at the poles.
Ozone is measured in Dobson Units (DU).
There is typically around 260 DU near the tropics and higher elsewhere.
Ozone is created when ultraviolet radiation (sunlight) strikes the stratosphere, splitting oxygen molecules (O₂) to atomic oxygen (O). The atomic oxygen quickly combines with other oxygen molecules to form ozone.

What are chloroflurocarbons (CFC's) and where do they come from?
http://www.atm.ch.cam.ac.uk/tour/index.html

Chloroflurocarbons are a common industrial product used in refrigeration systems, air conditioners, aerosols, solvents, etc.
They are inert in the lower atmosphere (troposphere) but are broken down into the components by the UV (ultraviolet) rays at higher altitudes.
The chlorine formed in this process damages the ozone.
The Montreal Protocol severely curtailed the manufacture of CFC's.
Factories and homes produce CFC's.

What is global warming?
http://www.koshlandsciencemuseum.org/
exhibitgcc/index.jsp

Global warming is an increase in the temperature outside. The current average global temperature is 57 Fahrenheit.
In the last 100 years, the average global temperature has risen 1 Fahrenheit.
In order for the earth to stay the same temperature from year to year, the energy arriving on Earth from the sun must be the same as the energy leaving the earth. If more energy leaves, the earth will cool down. If more stays, we will have global warming.
Scientists believe that the earth's temperature will go up 2 F to 6 F over the next century.
Carbon dioxide is the most common greenhouse gas. Because CO2 absorbs energy emitted from the earth and prevents it from going back out into space, it is called a greenhouse gas.

What are the ozone holes and where are they located?
http://www.atm.ch.cam.ac.uk/tour/index.html

The ozone hole should not be confused with global warming. There is a connection, but each is a separate issue.
The ozone hole occurs in the stratosphere, in the cold polar regions above the south pole.
The ozone has been depleted greatly in the last 15 years due to manmade chemicals.
The size of the ozone hole varies with the time of the year.
The Montreal Protocol in 1987 was aimed at reducing CFC's by half by the year 2000. Agreement has been reached on the control of industrial production of halocarbons until 2030.

What is the greenhouse effect?
http://liftoff.msfc.nasa.gov/academy/space/
greenhouse.html

The gases in the atmosphere let in light that warms the earth's surface, yet tends to prevent much of this heat from escaping. This natural warming of the planet is called the greenhouse effect.
The greenhouse gases are carbon dioxide, methane, nitrous oxide and a few others.
The greenhouse gases and clouds prevent some of the infrared radiation from escaping the earth's atmosphere. They trap the heat near Earth's surface where it warms the lower atmosphere.
Without the greenhouse gases, Earth would be much too cold for us to survive.
Greenhouse gases in the atmosphere can be seen from satellites in space.

Materials:

Expert Group worksheet
Internet connection
Text references

Evaluation:

CATEGORY	Excellent	Good	Satisfactory	Needs Improvement
Quality of Information	Information clearly relates to the groups topic. It includes several supporting details and/or examples.	Information clearly relates to the groups topic. It provides 1 to 2 supporting details and/or examples.	Information clearly relates to the groups topic. No details and/or examples are given.	Information has little or nothing to do with the groups topic.
Organization	Information is very organized with well-constructed paragraphs and subheadings.	Information is organized with well-constructed sentences.	Information is organized, but sentences are not well-constructed.	The information appears to be disorganized.
Amount of Information	Five facts are given and five questions asked about the topic.	Four facts are given and four questions asked about the topic.	Three facts are given and three questions asked about the topic.	Two facts are given and two questions asked about the topic.

CATEGORY	Excellent	Good	Satisfactory	Needs Improvement
Content	Shows a full understanding of the topic.	Shows a good understanding of the topic.	Shows a good understanding of parts of the topic.	Does not seem to understand the topic very well.
Preparedness	Student is completely prepared and has obviously rehearsed.	Student seems pretty well prepared but might have needed a couple more rehearsals.	The student is somewhat prepared, but it is clear that rehearsal was lacking.	Student does not seem at all prepared to present.
Stays on Topic	Stays on topic all (100%) of the time.	Stays on topic most (99%-90%) of the time.	Stays on topic some (89%-75%) of the time.	It was hard to tell what the topic was.
Enthusiasm	Facial expressions and body language generate a strong interest and enthusiasm about the topic in others.	Facial expressions and body language sometimes generate a strong interest and enthusiasm about the topic in others.	Facial expressions and body language are used to try to generate enthusiasm, but seem somewhat faked.	Very little use of facial expressions or body language. Did not generate much interest in topic being presented.