| 1. |
- Hansson, Hans Christen, et al.
(author)
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Long range aerosol transport in Southern Sweden : An example of multtvariate statistical evaluation methodology
- 1984
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In: Nuclear Inst. and Methods in Physics Research, B. - 0168-583X. ; 3:1-3, s. 483-488
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Journal article (peer-reviewed)abstract
- The utilization of multivariate statistical techniques is discussed with emphasis on the rather new method SIMCA, when applied to multielemental data. The procedures of scaling and normalizing are described. The data base used is from a project studying long range aerosol transport to southern Sweden. SIMCA reveals low variability in fine mode elemental composition in southerly air masses being clearly different from the elemental compositions found in northerly air masses.
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| 2. |
- Lannefors, Hans O., et al.
(author)
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Interelement and Multi-Station Concentration Evidence for Large Scale Aerosol Sulfur Transport across Sweden
- 1980
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In: Tellus, Series A: Dynamic Meteorology and Oceanography. - : Stockholm University Press. - 0280-6495. ; 32:6, s. 548-557
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Journal article (peer-reviewed)abstract
- The concentrations of sulfur and several more elements were measured in a network of six sites in southern Sweden. High time resolution samples were taken using a continuous filter sampler and analysed by particle induced X-ray emission (PIXE). Simultaneous increases in the sulfur concentrations were seen along the network due to the inflow of polluted air masses. High sulfur concentrations generally occurred during south-westerly to easterly air flow. Some of the episodes, distinguished by their shorter duration and their elevated vanadium and nickel concentrations, are suggested to be of local origin.
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| 3. |
- Martinsson, Bengt G., et al.
(author)
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Southern scandinavian aerosol composition and elemental size distribution characteristics dependence on air-mass history
- 1984
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In: Atmospheric Environment. - 0004-6981. ; 18:10, s. 2167-2182
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Journal article (peer-reviewed)abstract
- The influence of aerosol long range transport in southern Sweden was investigated from a data base consisting of simultaneous cascade impactor measurements at three sampling stations, two coastal and one inland rural location. The study focused on S and heavy metals determined by particle induced X-ray emission (PIXE) analysis. The influence of local emissions was minimized by eliminating samples which were strongly suspected to be contaminated. These were identified through size distribution alterations in combination with the concentration levels obtained. Based on air mass back trajectories the samples were classified into either a southern, a northern or an eastern sector or into one of the buffer sectors located in between the sectors mentioned above. Sector S elemental concentrations were generally one order of magnitude higher than those of sector N, while intermediate concentrations were found in the E sector. Intercomparisons of simultaneous fine mode elemental concentration measurements classified into sectors S and N, respectively, provides a method for calculating the sector S foreign contribution of the elemental concentrations in southern Sweden. These calculations, not based on emission data, result in a foreign contribution of the order of 50-90 % (lowest for components like V and Ni and highest for Ti, Mn and Zn) to the metal concentrations. The multivariate statistical method SIMCA revealed that the sector S aerosol elemental composition was dependent on particle size in the accumulation mode. Elements such as S and V (or Ni) normally assumed to originate mainly from the same sources (fossil fuel combustion) were clearly separated and instead S clustered with K, Mn and Zn. This indicates that the transformation processes are more important for the covariation of S with other elements than the source origin. Transformation of SO 2 in hygroscopic particles rich in K., Mn and Zn (compared with less hygroscopic particles rich in V and Ni) is a possible mechanism which would explain the results found.
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