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:
Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.
How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
15.12.2017 | Power and Electrical Engineering
15.12.2017 | Materials Sciences
15.12.2017 | Life Sciences