From the NILU annual report: NILU owns and operates a wide range of ‘background’ stations around Norway. Situated slightly off the beaten track, these stations measure atmospheric composition and deposition, contaminants, climate forcers, the ozone layer and UV radiation.
From Birkenes in the south, to Karpdalen in the north, you will find NILU’s monitoring stations for airborne contaminants. Some of them look like little log cabins, others are a simple plastic bucket in a rack. All are part of the network for monitoring air pollution in Norway.
Air pollution carried by wind and weather
– Just where these background stations are placed was determined long ago, says senior scientist Wenche Aas from NILU’s Department of Atmosphere and Climate.
– The aim was to get a good overview of the various types of pollutants found in the air above Norway, especially regarding what is carried here by the wind – so-called long-range air pollution. Thus, the stations are located in a way to minimise the impact of local emission sources.
The monitoring of sulphur content in air and precipitation began in 1972, as part of an extensive research project to study the effect of acid rain on forests and fisheries (the SNSF project). The project was later incorporated into the Norwegian Environment Agency’s national monitoring program, as well as in the European program EMEP (see fact box) and several other international networks.
In the beginning, the focus was on studying acid rain mainly received from emissions in Europe. The monitoring program gradually expanded to include other environmental topics, such as eutrophication, ground-level ozone, particulate matter, environmental contaminants and climate.
Station managers for generations
Engineers Dorothea Schulze and Andreas Fiskum both work in NILU’s Department of Monitoring and Instrumentation Technology. The department is responsible for maintaining the measuring instruments NILU uses for monitoring, and as part of the job, the engineers make regular maintenance visits to the various stations.
– The station managers are responsible for the daily operation, explains Dorothea.
– They are locals, often farmers, and they collect air and precipitation samples from “their” background stations every day, all year round. The samples are sent to NILU at Kjeller for analysis and registration.
– Without the station managers, we could not have had such a thorough monitoring program, says Andreas. – They take great pride in performing the job properly, and several of the station manager jobs have actually been passed down for generations.
Data through time and space
Scientists use data from the measuring stations to monitor how various pollutants are spreading through the atmosphere. These basic data are used to calculate exceedances of certain limits, e.g. acidification and eutrophication.
Emissions in Europe are still the main cause of acid rain in Norway. 90% of the sulphur deposited here is carried here from other countries. Nitrogen is to a greater degree derived from national emissions, including agriculture, but more than 70% of the nitrogen is transboundary.
– Data from the background stations gives us an overview of the country, and is used to monitor a wide variety of components, Aas explains. – They are useful both to identify new environmental challenges, and to see several components in different contexts, such as particles’ impact on health and climate. In addition, having continuous data from far back in time is extremely important to be able to follow the trends and the development of air pollution. We have much to thank our generations of station managers for.