Activity #1 – Graphing Ozone and Temperature Data
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:
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Graphing paper
Access to your collected ozone data, or a computer to download ozone data
Worksheet (included)
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
GO3 Ozone Data Graphing and Download: http://www.go3project.com/network2/index.php/pages/o3graph
Puerto Rico’s Group Page with solar intensity measurements:
http://www.go3project.com/network2/index.php/group/33
Instructions – Graphing Ozone and Temperature and Analyzing the Relationship
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.
Discussion – Interpreting the Graphs
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
2.
3.
4.
5.
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.
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.
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.
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.
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.
Worksheet – Graph Ozone and Temperature Data
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.
Date
Time
(hours)
8am
10am
12pm
2pm
4pm
6pm
8pm
10pm
12am
2am
4am
6am
8am
10am
12pm
2pm
4pm
6pm
8pm
10pm
12am
2am
4am
6am
8am
Ozone
(ppb)
Temperature
(F°)
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
Date
Time
Ozone (ppb)
Temperature (F°)
1
2
3
4
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.
Minimums
Date
Time
Ozone (ppb)
Temperature (F°)
1
2
3
4
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.