Supplementary material to "Carbonaceous aerosol source apportionment using the aethalometer model – Evaluation by radiocarbon and levoglucosan analysis at a rural background site in southern 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 the 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 showed good agreement for 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. A performed sensitivity analysis suggests that this discrepancy can be explained by interference of non-light-absorbing biogenic carbon during winter. 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.

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Carbonaceous aerosol source apportionment using the aethalometer model – Evaluation by radiocarbon and levoglucosan analysis at a rural background site in southern Sweden

10.5194/acp-2016-1005 ◽

2016 ◽

Author(s):

Johan Martinsson ◽

Hafiz Abdul Azeem ◽

Moa K. Sporre ◽

Robert Bergström ◽

Erik Ahlberg ◽

...

Keyword(s):

Source Apportionment ◽

Total Carbon ◽

Carbonaceous Aerosol ◽

High Time Resolution ◽

Southern Sweden ◽

Rural Background ◽

Aerosol Mass ◽

Carbon Mass ◽

Aerosol Source ◽

Good Agreement

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.

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Supplementary material to "Long-term chemical analysis and organic aerosol source apportionment at 9 sites in Central Europe: Source identification and uncertainty assessment"

10.5194/acp-2017-124-supplement ◽

2017 ◽

Author(s):

Kaspar R. Daellenbach ◽

Giulia Stefenelli ◽

Carlo Bozzetti ◽

Athanasia Vlachou ◽

Paola Fermo ◽

...

Keyword(s):

Chemical Analysis ◽

Source Apportionment ◽

Central Europe ◽

Source Identification ◽

Organic Aerosol ◽

Uncertainty Assessment ◽

Supplementary Material ◽

Aerosol Source

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Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-16369-2011 ◽

2011 ◽

Vol 11 (6) ◽

pp. 16369-16416 ◽

Cited By ~ 6

Author(s):

K. E. Yttri ◽

D. Simpson ◽

J. K. Nøjgaard ◽

K. Kristensen ◽

J. Genberg ◽

...

Keyword(s):

Source Apportionment ◽

Fossil Fuel ◽

Late Summer ◽

Latin Hypercube Sampling ◽

Total Carbon ◽

Carbonaceous Aerosol ◽

Anthropogenic Sources ◽

Minor Variation ◽

Rural Background ◽

Summer Time

Abstract. In the present study, natural and anthropogenic sources of particulate organic carbon (OCp) and elemental carbon (EC) have been quantified based on weekly filter samples of PM10 collected at four Nordic rural background sites (Birkenes (Norway), Hyytiälä (Finland) Vavihill (Sweden), Lille Valby (Denmark)) during late summer (5 August–2 September 2009). Levels of source specific tracers, i.e. cellulose, levoglucosan, mannitol and the 14C/12C ratio of total carbon (TC), have been used as input for source apportionment of the carbonaceous aerosol, whereas Latin Hypercube Sampling (LHS) was used to statistically treat the multitude of possible combinations resulting from this approach. The carbonaceous aerosol (here: TCp; i.e. particulate TC) was totally dominated by natural sources (69–86 %), with biogenic secondary organic aerosol (BSOA) being the single most important source (48–57 %). Interestingly, primary biological aerosol particles (PBAP) were the second most important source (20–32 %). The anthropogenic contribution was mainly attributed to fossil fuel sources (OCff and ECff (10–24 %), whereas no more than 3–7 % was explained by combustion of biomass (OCbb and ECbb in this late summer campaign i.e. emissions from residential wood burning and/or wild/agricultural fires. Fossil fuel sources totally dominated the ambient EC loading, accounting for 4–12 % of TCp, whereas <1.5 % was attributed to combustion of biomass. The carbonaceous aerosol source apportionment showed only minor variation between the four selected sites. However, Hyytiälä and Birkenes showed greater resemblance to each other, as did Lille Valby and Vavihill, the two latter being somewhat more influenced by anthropogenic sources. Ambient levels of organosulphates and nitrooxy-organosulphates in the Nordic rural background environment are reported for the first time in the present study. The most abundant organosulphate compounds were an organosulphate of isoprene and nitrooxy-organosulphates of α- and β-pinene and limonene.

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Supplementary material to "Organic aerosol source apportionment by offline-AMS over a full year in Marseille"

10.5194/acp-2017-54-supplement ◽

2017 ◽

Author(s):

Carlo Bozzetti ◽

Imad El Haddad ◽

Dalia Salameh ◽

Kaspar Rudolf Daellenbach ◽

Paola Fermo ◽

...

Keyword(s):

Source Apportionment ◽

Organic Aerosol ◽

Supplementary Material ◽

Aerosol Source

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Fossil versus contemporary sources of fine elemental and organic carbonaceous particulate matter during the DAURE campaign in Northeast Spain

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-23573-2011 ◽

2011 ◽

Vol 11 (8) ◽

pp. 23573-23618 ◽

Cited By ~ 5

Author(s):

M. C. Minguillón ◽

N. Perron ◽

X. Querol ◽

S. Szidat ◽

S. M. Fahrni ◽

...

Keyword(s):

Particulate Matter ◽

Organic Carbon ◽

Source Apportionment ◽

Biomass Burning ◽

Atmospheric Aerosols ◽

Fine Particulate Matter ◽

Western Mediterranean ◽

Carbonaceous Aerosol ◽

Carbonaceous Aerosols ◽

Background Site

Abstract. We present results from the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean), with the objective of apportioning the sources of fine carbonaceous aerosols. Submicron fine particulate matter (PM1) samples were collected during February-March 2009 and July 2009 at an urban background site in Barcelona (BCN) and at a forested regional background site in Montseny (MSY). We present radiocarbon (14C) analysis for elemental and organic carbon (EC and OC) and source apportionment for these data. We combine the results with those from component analysis of aerosol mass spectrometer (AMS) measurements, and compare to levoglucosan-based estimates of biomass burning OC, source apportionment of filter data with inorganic+EC+OC speciation, submicron bulk potassium (K) concentrations, and gaseous acetonitrile concentrations. At BCN, 87 % and 91 % of the EC on average, in winter and summer, respectively, had a fossil origin, whereas at MSY these fractions were 66 % and 79 %. The contribution of fossil sources to organic carbon (OC) at BCN was 40 % and 48 %, in winter and summer, respectively, and 31 % and 25 % at MSY. The combination of results obtained using the 14C technique, AMS data, and the correlations between fossil OC and fossil EC imply that the fossil OC at Barcelona is ~65 % primary whereas at MSY the fossil OC is mainly secondary (~85 %). Day-to-day variation in total carbonaceous aerosol loading and the relative contributions of different sources predominantly depended on the meteorological transport conditions. The estimated biogenic secondary OC at MSY only increased by ~40 % compared to the order-of-magnitude increase observed for biogenic volatile organic compounds (VOCs) between winter and summer, which highlights the uncertainties in the estimation of that component. Biomass burning contributions estimated using the 14C technique ranged from similar to higher than when estimated using other techniques, and the different estimations were highly or moderately correlated. Differences can be explained by the contribution of secondary organic matter (not included in the primary biomass burning source estimates), and/or by an overestimation of the biomass burning OC contribution by the 14C technique if the estimated biomass burning EC/OC ratio used for the calculations is too high for this region. Acetonitrile concentrations correlate well with the biomass burning EC determined by 14C. K is a noisy tracer for biomass burning.

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Source apportionment of carbonaceous aerosol in southern Sweden

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-11387-2011 ◽

2011 ◽

Vol 11 (22) ◽

pp. 11387-11400 ◽

Cited By ~ 54

Author(s):

J. Genberg ◽

M. Hyder ◽

K. Stenström ◽

R. Bergström ◽

D. Simpson ◽

...

Keyword(s):

Organic Carbon ◽

Source Apportionment ◽

Fossil Fuels ◽

Elemental Carbon ◽

Transport Model ◽

Total Carbon ◽

Carbonaceous Aerosol ◽

Anthropogenic Sources ◽

Biomass Combustion ◽

Southern Sweden

Abstract. A one-year study was performed at the Vavihill background station in southern Sweden to estimate the anthropogenic contribution to the carbonaceous aerosol. Weekly samples of the particulate matter PM10 were collected on quartz filters, and the amounts of organic carbon, elemental carbon, radiocarbon (14C) and levoglucosan were measured. This approach enabled source apportionment of the total carbon in the PM10 fraction using the concentration ratios of the sources. The sources considered in this study were emissions from the combustion of fossil fuels and biomass, as well as biogenic sources. During the summer, the carbonaceous aerosol mass was dominated by compounds of biogenic origin (80%), which are associated with biogenic primary and secondary organic aerosols. During the winter months, biomass combustion (32%) and fossil fuel combustion (28%) were the main contributors to the carbonaceous aerosol. Elemental carbon concentrations in winter were about twice as large as during summer, and can be attributed to biomass combustion, probably from domestic wood burning. The contribution of fossil fuels to elemental carbon was stable throughout the year, although the fossil contribution to organic carbon increased during the winter. Thus, the organic aerosol originated mainly from natural sources during the summer and from anthropogenic sources during the winter. The result of this source apportionment was compared with results from the EMEP MSC-W chemical transport model. The model and measurements were generally consistent for total atmospheric organic carbon, however, the contribution of the sources varied substantially. E.g. the biomass burning contributions of OC were underestimated by the model by a factor of 2.2 compared to the measurements.

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