Ambient Air Monitoring Stations in The Reykjavik Metro Area

When it comes to air pollution, it is important for all stakeholders to realize where it originates from.

01

About project

One of the benefits of VDV is the ability to perform analysis using data from several different instruments.  In the case of ambient air monitoring, it is not only the general strength of the parameters measured that is of interest, but also the actual direction to the source and the time of day when the readings are high.  These reports are easily created in VDV with few keystrokes.

— Andres Thorarinsson, Vista Engineering
02

The challenge

The challenge is often to know the true source of air pollution. For companies with factories it is for example important to know if specific pollution is coming from their factories or maybe from other sources?

03

The solution

By correlating weather data with air quality data it is possible to understand where the air pollution originates.

There are several Ambient Air Monitoring Stations in the Reykjavik Metro Area.  The instruments in these Monitoring Stations are mostly of the type Thermo Fisher, Grimm, Airpointer and Horiba. Weather stations are equipped with Campbell Dataloggers and RM Young Wind meter.  The parameters measured are NO, NOx, NO2, H2S, SO2 and dust 2.5 and 10.  Most often the measurement sites are equipped with a weather station with instruments for wind speed and wind direction, as well as for temperature, atmospheric air pressure and RH%.  Each station is equipped with a data logger and telemetry, and all data is collected and stored in a VDV database.

The data shown here is from an ambient air monitoring station in the middle of an industrial park and close to a highway.  Most commonly such data is presented on trend graphs where it is easy to get the general overview.

Two months of data is shown on the graph. While this presentation is informative it is hard to make any conclusions about the origin of air pollution by just looking at the trend lines.

However, there are several VDV tools which are very useful for this kind of ambient air data analyzing; the Wind Rose (and its partner The Filter Wind Rose), the Intensity Plot and the XY-graph.  These tools greatly shorten the road to the conclusion.

As for general wind analyze the Wind Rose is very useful and tells what to expect. In this case the Wind Rose shows that for this time period wind is mostly blowing from NE and SE.
Filter Wind Rose is very useful to find the actual direction to the source. It makes it possible to visualize the wind direction based on a given range for pollution. When the SO2 time series are displayed on a Filtered Wind Rose it becomes clear that large portion of SO2 is coming from an industrial facility located west of the monitoring Site.
Filter Wind Rose plotting H2S shows that the source is north east of the monitoring Site. In that direction there is a geothermal plant which is the source.
2 months of NO2 data is plotted on the Intensity Plot. Clearly the concentration is highest during Monday to Friday, from at 8 AM to around 11 PM. Therefore, the strength of NO2 is highly connected to working hours and traffic.
04

The results

With the use of Wind Roses it is possible to conclude that SO2 is coming from the industrial facility, but H2S and NO2 is not. H2S is originated from a Geothermal plant located north east of the monitoring site and NO2 is connected to office hours and traffic.

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