New European air chemistry forecast service

We all know how much the weather affects our everyday lives, but variations in the chemical composition of the air also play a decisive role, mainly, perhaps, in terms of the climate and for our health. Now a completely new European air chemistry forecast service is being established.

The chemical composition of the atmosphere has a noticeable effect on life on Earth. The list of factors that affect us is potentially endless, such as solar radiation, carbon dioxide, methane, ozone and particles. SMHI is one of the prime movers behind a new European air chemistry service which will be providing basic forecasts, analyses and data.

Air quality and greenhouse gas levels

There are already many examples of this new air chemistry information. Air quality forecasts show predicted ground level ozone levels. Other services that affect people's health include carbon dioxide and particle levels. UV forecasts indicate current levels of the harmful component of the sun's radiation.

Solar radiation forecasts also tell us how the solar energy supply is varying. On the climate side, reports tell us how much greenhouse gas, such as carbon dioxide and methane, there is in the atmosphere.

“This is becoming a broad spectrum of air chemistry information. The results, presented on a web portal, can be used by individuals, decision-makers and researchers. Others can use these services to create new products – the possibilities are endless,” says Robertson.

One example of the new air chemistry service is ground-level ozone forecasts for three days ahead.

Satellite readings tell us more

The work on creating a totally new infrastructure for the forecast service is far-reaching. One important part is using readings from satellites and the ground in advanced computer calculations in a better way than we could before. The theoretical results will also be compared continuously with actual observations for better quality. Another key idea is that the air chemistry calculations will be carried out by a number of parties: that means a whole series of results, known as ensembles, can be presented, making the results more usable and improving the reliability of supply.

“This is closely connected to the work on calculating the spread of the volcanic ash from Iceland. Experience from this shows amongst other things how important it is to be able to use more observation data, not only as the basis for calculations, but also to verify the calculation results,” says Robertson.

The MACC (Monitoring atmospheric composition and climate) project will run until next autumn. SMHI is one of six main parties involved, and is contributing air chemistry calculations using the regional calculation model MATCH. MACC is part of the EU's Global Monitoring for Environment and Security venture.

Examples of air chemistry forecasts and analyses are already available on the project website at

Luftkemi verifikationer
The new services include more observation data. The picture shows calculations and observations (shown as small circles on the map).
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Luftkemi ensembler
The air chemistry calculations are made by several different models. These are presented as intervals in the graph and give for example a good picture of the certainty in the results.
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