Activity Description and Objectives: The purpose of this activity is for students to familiarize themselves with student collected ozone data. They will also learn how to graph two variables simultaneously to discover relationships and trends in their data. In this exercise, they will graph ozone and temperature by hand on graphing paper. Alternatively, they can graph their data online at the GO3 Project website.
Materials:

Graphing paper
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Access to your collected ozone data, or a computer to download ozone data
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Worksheet (included)
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Computer (if they will be graphing the data online)
Websites Used in the Activity:
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GO3 Curriculum, Lessons 7 and 11: http://www.go3project.com/network2/index.php/pages/curriculumdownloads
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GO3 Ozone Data Graphing and Download: http://www.go3project.com/network2/index.php/pages/o3graph
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Puerto Rico’s Group Page with solar intensity measurements: http://www.go3project.com/network2/index.php/group/33
1.
In this activity, the students will look at their collected data to record and graph ozone and temperature data. You can assist them in copying values from your GO3 Computer’s software into their worksheet. They will record one value every two hours for a 48 hour period. They can either look at their computer and scroll through the collected data, or get a list of data online by selecting
List instead of Graph in the online graphing area of go3project.com. They also have the option of graphing data from another school, which they can also get online. In either case, have them record the measurement closest to the time listed the worksheet for each hour.
2.
They will use these values to plot ozone and temperature vs. time.
3.
Note: it is easier to see the relationship in summer data. To use summer data, download the data from the GO3 Project website under the GO3 Data tab.
1.
Through plotting two variables simultaneously, the students can start to identify trends and relationships between weather and ozone. Although temperate and ozone are correlated, they do not have a direct cause and effect relationship. Ozone tends to follow temperature trends because of both variables’ direct relationship with solar intensity, not necessarily because increased temperature leads to increased ozone formation. However, higher temperatures speed up the

reactions that form ozone, so there is the indirect relationship that when temperature is high there is a higher likelihood of increased ozone production. The temperature effect on ozone production is relatively small, however.
2.
There is a much more direct correlation between solar intensity and ozone production. The GO3 school in Puerto Rico posts their solar intensity measurements every day on the social network.
They also post a graph of solar intensity and ozone every week or so. Contact them to discuss their findings and correlations between ozone and solar intensity. A link to their group is listed above.
3.
In some locations, ozone does not go to zero at night. This seems to occur more frequently in remote, or mountain sites. Scientists don’t know exactly what is going on, but it could be related to the amount of NOx at those sites. When there is a lot of NOx in the air, it quickly reacts with ozone at night and destroys it. The other way ozone is destroyed is by reacting with surfaces, known as surface deposition. Perhaps at these sites there is not enough ozone destruction due to surface deposition to destroy all the ozone, and not enough NOx to destroy the rest. You can see in the highly polluted areas around the world with a lot of NOx that ozone goes to zero every night.
4.
Some locations that would be expected to have high ozone have relatively low ozone peaks. This can be because of high NOx emissions. High concentrations of NOx can actually lead to low ozone concentrations, because the reactions between ozone and NO can lead to the net destruction of ozone. This can sometimes explain relatively low ozone concentrations in highly polluted locations.
This is one example of the complicated atmospheric chemistry behind ozone formation and that ozone formation happens under very specific conditions and certain emissions.
5.
There can be multiple peaks in a day, although one peak in the late afternoon is the typical pattern.
There can be a peak at night, which would most likely represent ozone transported from an upwind location to your site.

Data Collection: Using your Data Collection Software, or an online list of your data, record the values of ozone and temperature in the data table provided. You can pick any two days that you have continuous data for.
Below is a chart of ozone concentrations and their relative impact on human health. This will help you interpret your data as it relates to your health.
0-60ppb
61-75ppb
76-95ppb
96-115ppb
116-375ppb
376-449ppb
450ppb +
Good
Moderate
Unhealthy if Sensitive
Unhealthy
Very Unhealthy
Hazardous
Questionable Data
Graph your Data: After you have filled out your data table, graph both temperature and ozone on a line graph on your graphing paper, with time and date on the x-axis and ozone and temperature on the y-axis.

Identifying Points on Your Graphs:
Locate and mark the regions on your graphs where you see the peak (maximum) values of ozone. Record the time of day, the ozone concentration and the temperature associated with each peak. You could have only two peaks, or you could see more. Record information for up to four peaks.
Peaks
1
2
3
4
Date Time Ozone (ppb) Temperature (F°)
Also locate and mark the regions on your graph where you see the minimum values of ozone. Note the time of day, the amount of ozone and the temperature associated with up to four minimums.
Date Time Ozone (ppb) Minimums
1
2
3
4
Temperature (F°)
Concluding Questions: After you have created your graphs and identified important points on your graphs, answer the following questions. Use the back if you need to.
1.
What is the maximum ozone concentration you saw during this time period (don’t forget units)?
2.
Using the scale for ozone concentrations and human health above, what range is your peak concentration in, for example Good, Unhealthy, etc.?
3.
Why do we typically see peak ozone formation in the late afternoon?
4.
Why does ozone decrease to nearly zero at night?
5.
What is the difference between a cause and effect relationship between variables, as opposed to a casual relationship?
6.
Post your results on the GO3 Social Network and compare your data with other schools!

Here is an example of a graph of ozone and temperature for a 48-hour period. You will create a similar graph, either by hand or online, in this exercise.