Cold winters mean more pollution

Feb 22, 2011
The air quality in Gothenburg is linked to differences in air pressure over the North Atlantic. Credit: University of Gothenburg

Differences in air pressure over the North Atlantic have meant that the last two winters in Gothenburg, Sweden, have been extremely cold. This has led to the air in Gothenburg being more polluted with nitrogen oxides than ever before. A new study from the University of Gothenburg shows that there is a strong link between climate and air pollution.

The in Gothenburg and large parts of North-West Europe is partly down to the (NAO), in other words the differences in over the North Atlantic. The NAO swings between positive and negative phases depending on the differences in air pressure between Iceland and the Azores. When the NAO is in a negative phase – as has been the case during the last two winters – the city has cold winters because the low pressure sits over southern Europe, while cold air from the polar region or Siberia sits over northern Europe.

In a study carried out in Gothenburg, a group of researchers from the University of Gothenburg investigated how the concentrations of nitrogen oxides (NO and NO2) in the air can be linked to the weather. Published in the scientific journal Atmospheric Environment, the study shows that the air quality standard has been exceeded more and more frequently during periods of a negative NAO even though emissions have fallen in the city centre since 2000 according to official measurements from the Environmental Administration.

"These extremely cold winters in Gothenburg, with high cold air, bring a clear deterioration in air quality," says Maria Grundström from the University of Gothenburg's Department of Plant and Environmental Sciences, one of the researchers behind the study. "With typical Gothenburg weather – low air pressure with precipitation and strong winds – the air pollution is dispersed more quickly on account of better air mixing."

Air mixing is often poor in Gothenburg during the months when the NAO is negative. This means that emitted at ground level accumulates and that the air quality becomes very poor. During the winter months of 1997 to 2006, concentrations of were around 18% higher during months when the NAO was negative than when it was positive.

Air quality standards for nitrogen dioxide (NO2) were exceeded far more often when the NAO was in a negative phase. The researchers refer, for example, to the fact that the number of exceedances of the hourly limit for nitrogen dioxide (90 µg/m3) increased. This can be linked to the fact that the NAO has tended increasingly to be in a negative phase during the winter months over the last two years.

The study was carried out by Maria Grundström, Jenny Klingberg and Håkan Pleijel from the Department of Plant and Environmental Sciences at the University of Gothenburg, and researcher Hans Linderholm from the Department of Earth Sciences at the University of Gothenburg.

Explore further: Actions on climate change bring better health, study says

add to favorites email to friend print save as pdf

Related Stories

Rapid changes in the winter climate

Aug 14, 2009

The Baltic Sea winter climate has changed more in the last 500 years than previously thought. Research at the University of Gothenburg, Sweden, shows that our part of the world has experienced periods of both ...

The grass is greener after a cold winter

Jan 25, 2006

We may well be shivering through an unusually chilly winter, but the dip in temperature is not all bad news, at least for your lawn. Researchers at Harper Adams University College, Shropshire, believe a cold winter leads ...

Study says Chinese air quality standards not yet met

May 13, 2008

With the Olympic Games in sight, the Chinese Government is committed to improving the air quality in Beijing, and has had measures in place since 1998 which have already made a difference. However, there is still some way ...

Recommended for you

Implications for the fate of green fertilizers

19 hours ago

The use of green fertilizers is a practice that has been around since humans first began growing food, but researchers are warning that modern techniques for the creation of these fertilizers could have implications ...

User comments : 0