The winter weather in Gothenburg and large parts of North-West Europe is partly down to the North Atlantic Oscillation (NAO), in other words the differences in air pressure 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 air pollution emitted at ground level accumulates and that the air quality becomes very poor. During the winter months of 1997 to 2006, concentrations of nitrogen oxides 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 climate researcher Hans Linderholm from the Department of Earth Sciences at the University of Gothenburg.
The article, Urban NO2 and NO pollution in relation to the North Atlantic Oscillation NAO, published in Atmospheric Environment, can be downloaded from: http://dx.doi.org/10.1016/j.atmosenv.2010.11.023For further information, please contact:
Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
27.06.2017 | Power and Electrical Engineering
27.06.2017 | Information Technology
27.06.2017 | Physics and Astronomy