Publications

The IMPACTs project and recent developments of EMEP.

Tørseth, K.

The importance of applying "clean" and validated quantification techniques for studying environmental levels of materials used by consumers. Poster presentation. NILU F

Salvito, D.T.; Kallenborn, R.; Chiu, P.; Allen, H.E.

The importance of biomass burning as a source of BC in the European Arctic - Based on measurements at the Zeppelin Observatory, Svalbard. NILU F

Myhre, C.L.; Yttri, K.E.; Eckhardt, S.; Stohl, A.; Fiebig, M.; Dye, C.; Ström, J.; Klimont, Z.

The importance of diet on exposure to and effects of persistent organic pollutants on human health in the Arctic.

Odland, J.O.; Deutch, B.; Hansen, J.C.; Burkow, I.C.

The importance of nitrogen oxides for the exceedance of critical thresholds in the Nordic countries.

Johansson, M.; Suutari, R.; Bak, J.; Lövblad, G.; Posch, M.; Simpson, D.; Tuovinen, J.P.; Törseth, K.

The importance of temporal variables in environmental modelling: Rationalizing measured concentrations of cyclic volatile methyl siloxanes in an Arctic lake.

Krogseth, I.S.; Whelan, M.J.; Christensen, G.N.; Breivik, K.; Evenset, A.; Warner, N.A.

The influence of UVR and climate conditions on fish stocks: a case study of the Northeast arctic cod (UVAC). NILU F

Hansen, G.

The influence of background ozone concentrations on the emission abatement strategies (NEPAP WP 2). NILU F

Solberg, S.

The influence of cruise ship emissions on air pollution in Svalbard.

Eckhardt, S.; Hermansen, O.; Grythe, H.; Fiebig, M.; Stebel, K.; Cassiani, M.; Baecklund, A.; Stohl, A.

The influence of particles on ozone depletion - model calculations. Risø-R-934(EN)

Fløisand, I.; Stordal, F.; Larsen, N.; Knudsen, B.; Rognerud, B.; Isaksen, I S A.

The influence of probe spacing and probe bias in a double Langmuir probe setup

Kjølerbakken, Kai Morgan; Miloch, Wojciech Jacek; Røed, Ketil

Multi-needle Langmuir probes are mounted on satellites and sounding rockets for high-frequency characterization of plasma in the ionosphere. Mounted on a spacecraft, the recorded probe current often differs from expected results. In this paper, we perform a numerical study using a particle in cell model to see how the spacing between the individual probes used in a multi-needle setup influences the measured current. We also study how the applied probe bias voltage can contribute to deviations. In our study, we use realistic electron temperatures and electron densities for the relevant part of the ionosphere. However, the results should be generally applicable and valid for other space environments as well as for laboratory Langmuir probe applications. From our study, we can see that when the distance is short, less than two Debye lengths, the current is highly affected, and we can see deviations of more than 60% compared to a single probe setup.

AIP Publishing (American Institute of Physics)

The influence of residential wood combustion on the concentrations of PM2.5 in four Nordic cities

Kukkonen, Jaakko; Lopez-Aparicio, Susana; Segersson, David; Geels, Camilla; Kangas, Leena; Kauhaniemi, Mari; Maragkidou, Androniki; Jensen, Anne; Assmuth, Timo; Karppinen, Ari; Sofiev, Mikhail; Hellén, Heidi; Riikonen, Kari; Nikmo, Juha; Kousa, Anu; Niemi, Jarkko; Karvosenoja, Niko; Sousa Santos, Gabriela; Sundvor, Ingrid; Im, Ulas; Christensen, Jesper H.; Nielsen, Ole-Kenneth; Plejdrup, Marlene S.; Nøjgaard, Jacob Klenø; Omstedt, Gunnar; Andersson, Camilla; Forsberg, Bertil; Brandt, Jørgen

Residential wood combustion (RWC) is an important contributor to air quality in numerous regions worldwide. This study is the first extensive evaluation of the influence of RWC on ambient air quality in several Nordic cities. We have analysed the emissions and concentrations of PM2.5 in cities within four Nordic countries: in the metropolitan areas of Copenhagen, Oslo, and Helsinki and in the city of Umeå. We have evaluated the emissions for the relevant urban source categories and modelled atmospheric dispersion on regional and urban scales. The emission inventories for RWC were based on local surveys, the amount of wood combusted, combustion technologies and other relevant factors. The accuracy of the predicted concentrations was evaluated based on urban concentration measurements. The predicted annual average concentrations ranged spatially from 4 to 7 µg m−3 (2011), from 6 to 10 µg m−3 (2013), from 4 to more than 13 µg m−3 (2013) and from 9 to more than 13 µg m−3 (2014), in Umeå, Helsinki, Oslo and Copenhagen, respectively. The higher concentrations in Copenhagen were mainly caused by the relatively high regionally and continentally transported background contributions. The annual average fractions of PM2.5 concentrations attributed to RWC within the considered urban regions ranged spatially from 0 % to 15 %, from 0 % to 20 %, from 8 % to 22 % and from 0 % to 60 % in Helsinki, Copenhagen, Umeå and Oslo, respectively. In particular, the contributions of RWC in central Oslo were larger than 40 % as annual averages. In Oslo, wood combustion was used mainly for the heating of larger blocks of flats. In contrast, in Helsinki, RWC was solely used in smaller detached houses. In Copenhagen and Helsinki, the highest fractions occurred outside the city centre in the suburban areas. In Umeå, the highest fractions occurred both in the city centre and its surroundings.