Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
doi:10.5194/acp-2016-1005
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
15 Dec 2016
Review status
A revision of this discussion paper was accepted for the journal Atmospheric Chemistry and Physics (ACP) and is expected to appear here in due course.
Carbonaceous aerosol source apportionment using the aethalometer model – Evaluation by radiocarbon and levoglucosan analysis at a rural background site in southern Sweden
Johan Martinsson1,2, Hafiz Abdul Azeem3, Moa K. Sporre4, Robert Bergström5,6, Erik Ahlberg1,2, Emilie Öström1,2, Adam Kristensson1, Erik Swietlicki1, and Kristina Eriksson Stenström1 1Division of Nuclear Physics, Lund University, Box 118, 22100, Lund, Sweden
2Centre for Environmental and Climate Research, Lund University, Ecology Building, 22362, Lund, Sweden
3Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Lund, Box 118, 22100, Lund, Sweden
4Department of Geosciences, University of Oslo, Postboks 1022, Blindern, 0315, Oslo, Norway
5Swedish Meteorological and Hydrological Institute, 60176, Norrköping, Sweden
6Department of Chemistry, University of Gothenburg, 41296, Gothenburg, Sweden
Abstract. With the present demand on fast and inexpensive aerosol source apportionment methods, the aethalometer model was evaluated for a full seasonal cycle (June 2014–June 2015) at a rural atmospheric measurement station in southern Sweden by using radiocarbon and levoglucosan measurements. By utilizing differences in absorption of UV and IR, the aethalometer model apportions carbon mass into wood burning (WB) and fossil fuel combustion (FF) aerosol. In this study, a small modification in the model in conjunction with carbon measurements from thermal-optical analysis allowed apportioned non-light absorbing biogenic aerosol to vary in time. The absorption differences between WB and FF can be quantified by the absorption Ångström exponent (AAE). In this study AAEWB was set to 1.81 and AAEFF to 1.0. Our observations show that AAE was elevated during winter (1.36 ± 0.07) compared to summer (1.12 ± 0.07). Quantified WB aerosol showed good agreement with levoglucosan concentrations, both in terms of correlation (R2 = 0.70) and in comparison to reference emission inventories. WB aerosol showed strong seasonal variation with high concentrations during winter (0.65 µg m−3, 56 % of total carbon) and low concentrations during summer (0.07 µg m−3, 6 % of total carbon). FF aerosol showed less seasonal dependence, however black carbon (BC) FF showed clear diurnal patterns corresponding to traffic rush hour peaks. The presumed non-light absorbing biogenic carbonaceous aerosol concentration was high during summer (1.04 µg m−3, 72 % of total carbon) and low during winter (0.13 µg m−3, 8 % of total carbon). Aethalometer model results were further compared to radiocarbon and levoglucosan source apportionment results. The comparison displayed good agreement in apportioned mass of WB and biogenic carbonaceous aerosol but discrepancies were found for FF aerosol mass. The aethalometer model overestimated FF aerosol mass by a factor of 1.3 compared to radiocarbon and levoglucosan source apportionment. This discrepancy may possibly be explained by a relatively low R2 value in the fit of FF aerosol light absorption to carbon mass concentration. In summary, the aethalometer model offers a cost-effective, yet robust high-time resolution source apportionment at rural background stations compared to a radiocarbon and levoglucosan alternative.

Citation: Martinsson, J., Abdul Azeem, H., Sporre, M. K., Bergström, R., Ahlberg, E., Öström, E., Kristensson, A., Swietlicki, E., and Eriksson Stenström, K.: Carbonaceous aerosol source apportionment using the aethalometer model – Evaluation by radiocarbon and levoglucosan analysis at a rural background site in southern Sweden, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1005, in review, 2016.
Johan Martinsson et al.
Johan Martinsson et al.

Viewed

Total article views: 184 (including HTML, PDF, and XML)

HTML PDF XML Total Supplement BibTeX EndNote
135 38 11 184 11 4 12

Views and downloads (calculated since 15 Dec 2016)

Cumulative views and downloads (calculated since 15 Dec 2016)

Viewed (geographical distribution)

Total article views: 184 (including HTML, PDF, and XML)

Thereof 184 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 26 Mar 2017
Publications Copernicus
Download
Short summary
In this study we have focused our attention to the sources atmospheric carbon particles. More specifically, we are evaluating a fast and inexpensive method which determines the source of these particles by utilizing light absorption by the particles. We found that this method is suitable for source estimation by comparing it to another method based on carbon isotopes and chemical tracer molecules. Cheap and fast methods based on light absorption can be utilized widely to deduce particle sources.
In this study we have focused our attention to the sources atmospheric carbon particles. More...
Share