Activities: Traffic, nitrogen oxide and ozone analysis in your town

Investigate how much traffic is observable in your town and if you find links to the concentrations of nitrogen oxides and ozone. How do they change during the day?

Background:

There are links between the traffic in the streets, the local weather situation and the concentrations of nitrogen oxides (NO, NO₂) and ozone in the towns and the suburbs of the town. If your school is close to a station of the local air quality network, we encourage you to investigate the traffic intensity and the concentration of air pollutants in the streets near to your school.

Material and conditions:

Ideal conditions would be if the school had one or even more mobile ozone detectors available.
 

Since this is usually not the case, please check if there is a measurement point of the local air quality network installed. Such points often look like a small metal building or box on the street as for construction working and have some instruments on top. (see image)

Their location can often be found out checking the website of the local air quality monitoring maintained by the local, regional or state administration. Please check also if the data automatically generated in this station can be accessed online on the Internet. Alternatively, please ask the local officers of the air quality monitoring for assistance and data.
 

If you are used to working in geography with geographic information systems (GIS), you may develop a small map of the traffic intensity for different times of the day and use this in a GIS software.
An example of free GIS software is SAGA GIS: www.saga-gis.org

For this you need geo-referenced maps from your region. If you do not have access to them, you may work for example with Google Earth.

If a “field experiment” is not possible during the classes, you may also work with data from stations in your region and analyse them in the classroom as shown in the example below.
 

Objective:
 
Investigate if and how the local ozone production is related to the traffic near to the station or in the region of the station. If an ozone detector is available in your school, you can measure ozone yourself.
It is recommended to choose a sunny day in spring, summer or early autumn.
 

Task:
 
Measure the traffic intensity in a street or several streets next to one or two ozone measurements points. For this purpose, count cars over a well-defined time period at different times of the day. Compare with ozone values.
 

What has to be considered?

If the measurement point for ozone is next to a busy street it is likely that local ozone is depleted by the NO emissions from traffic. Such stations are suitable for the parallel analysis of nitrogen oxide data and comparison of data from traffic counting.

If the measurement point for ozone is in a housing area or a suburb it is likely that the role of local traffic is minor. If you choose places for traffic counting, consider major streets in the vicinity, but do not expect a strong dependence.

Please consider the wind direction. Choose places for the traffic counting which are located in a way that the wind blows from the street where you count cars to the measurement point.