scholarly journals Fossil and non-fossil sources of organic carbon (OC) and elemental carbon (EC) in Göteborg, Sweden

2009 ◽  
Vol 9 (5) ◽  
pp. 1521-1535 ◽  
Author(s):  
S. Szidat ◽  
M. Ruff ◽  
N. Perron ◽  
L. Wacker ◽  
H.-A. Synal ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Elemental Carbon ◽  
Latin Hypercube Sampling ◽  
Water Soluble ◽  
Total Carbon ◽  
Rural Site ◽  
Urban Site ◽  
Winter Period ◽  
Back Trajectories ◽  
Wood Burning

Abstract. Particulate matter was collected at an urban site in Göteborg (Sweden) in February/March 2005 and in June/July 2006. Additional samples were collected at a rural site for the winter period. Total carbon (TC) concentrations were 2.1–3.6 μg m−3, 1.8–1.9 μg m−3, and 2.2–3.0 μg m−3 for urban/winter, rural/winter, and urban/summer conditions, respectively. Elemental carbon (EC), organic carbon (OC), water-insoluble OC (WINSOC), and water-soluble OC (WSOC) were analyzed for 14C in order to distinguish fossil from non-fossil emissions. As wood burning is the single major source of non-fossil EC, its contribution can be quantified directly. For non-fossil OC, the wood-burning fraction was determined independently by levoglucosan and 14C analysis and combined using Latin-hypercube sampling (LHS). For the winter period, the relative contribution of EC from wood burning to the total EC was >3 times higher at the rural site compared to the urban site, whereas the absolute concentrations of EC from wood burning were elevated only moderately at the rural compared to the urban site. Thus, the urban site is substantially more influenced by fossil EC emissions. For summer, biogenic emissions dominated OC concentrations most likely due to secondary organic aerosol (SOA) formation. During both seasons, a more pronounced fossil signal was observed for Göteborg than has previously been reported for Zurich, Switzerland. Analysis of air mass origin using back trajectories suggests that the fossil impact was larger when local sources dominated, whereas long-range transport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations of levoglucosan and other monosaccharide anhydrides were low for the urban and the rural site in the area of Göteborg during winter.

scholarly journals Fossil and non-fossil sources of organic carbon (OC) and elemental carbon (EC) in Göteborg, Sweden

2008 ◽  
Vol 8 (4) ◽  
pp. 16255-16289 ◽  
Author(s):  
S. Szidat ◽  
M. Ruff ◽  
L. Wacker ◽  
H.-A. Synal ◽  
M. Hallquist ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Elemental Carbon ◽  
Latin Hypercube Sampling ◽  
Water Soluble ◽  
Rural Site ◽  
Urban Site ◽  
Winter Period ◽  
Back Trajectories ◽  
Relative Contribution ◽  
Wood Burning

Abstract. Particulate matter was collected at an urban site in Göteborg (Sweden) in February/March 2005 and in June/July 2006. Additional samples were collected at a rural site for the winter period. Elemental carbon (EC), organic carbon (OC), water-insoluble OC (WINSOC), and water-soluble OC (WSOC) were analyzed for 14C in order to distinguish fossil from non-fossil emissions. As wood burning is the single major source of non-fossil EC, its contribution can be quantified directly. For non-fossil OC, the wood burning fraction was determined independently by levoglucosan and 14C analysis and combined using Latin-hypercube sampling (LHS). For the winter period, the relative contribution of EC from wood burning to the total EC was >3 times higher at the rural site compared to the urban site, whereas the absolute concentrations of EC from wood burning were comparable at both sites. Thus, the urban site is substantially more influenced by fossil EC emissions. For summer, biogenic emissions dominated OC concentrations most likely due to secondary organic aerosol (SOA) formation. During both seasons, a more pronounced fossil signal was observed for Göteborg than has previously been reported for Zurich, Switzerland. Analysis of air mass origin using back trajectories suggests that the fossil impact was larger when local sources dominated, whereas long-range transport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations of levoglucosan and other monosaccharide anhydrides were low for the urban and the rural site in the area of Göteborg during winter. The comparison of summer and winter results provides insight into the annual cycle of anthropogenic vs. biogenic contributions to the atmospheric aerosol.

scholarly journals Contributions of biomass/biofuel burning to organic aerosols and particulate matter in Tanzania, East Africa, based on analyses of ionic species, organic and elemental carbon, levoglucosan and mannosan

2013 ◽  
Vol 13 (20) ◽  
pp. 10325-10338 ◽  
Author(s):  
S. L. Mkoma ◽  
K. Kawamura ◽  
P. Q. Fu
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
East Africa ◽  
Biomass Burning ◽  
Elemental Carbon ◽  
Dry Season ◽  
Water Soluble ◽  
Total Carbon ◽  
Rural Site ◽  
Pm2.5 And Pm10

Abstract. Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania, East Africa, in 2011 during wet and dry seasons and were analysed for carbonaceous components, levoglucosan, mannosan and water-soluble inorganic ions. The contributions of biomass/biofuel burning to the organic carbon (OC) and particulate matter (PM) mass were estimated to be 46–52% and 87–13%, respectively. The mean mass concentrations of PM2.5 and PM10 were 28 ± 6 μg m−3 and 47 ± 8 μg m−3 in wet season, and 39 ± 10 μg m−3 and 61 ± 19 μg m−3 in dry season, respectively. Total carbon (TC) accounted for 16–19% of the PM2.5 mass and 13–15% of the PM10 mass. On average, 86 to 89% of TC in PM2.5 and 87 to 90% of TC in PM10 was OC, of which 67–72% and 63% was found to be water-soluble organic carbon (WSOC) in PM2.5 and PM10, respectively. We found that concentrations of levoglucosan and mannosan (specific organic tracers of pyrolysis of cellulose) well correlated with non-sea-salt potassium (nss-K+) (r2 = 0.56–0.75), OC (r2 = 0.75–0.96) and WSOC (r2 = 0.52–0.78). The K+ / OC ratios varied from 0.06 to 0.36 in PM2.5 and from 0.03 to 0.36 in PM10 with slightly higher ratios in dry season. Mean percent ratios of levoglucosan and mannosan to OC were found to be 3–4% for PM2.5 and PM10 in both seasons. We found lower levoglucosan / K+ ratios and higher K+ / EC (elemental carbon) ratios in the biomass-burning aerosols from Tanzania than those reported from other regions. This feature is consistent with the high levels of potassium reported in the soils of Morogoro, Tanzania, suggesting an importance of direct emission of potassium by soil resuspension although K+ is present mostly in fine particles. It is also likely that biomass burning of vegetation of Tanzania emits high levels of potassium that may be enriched in plant tissues. The present study demonstrates that emissions from mixed biomass- and biofuel-burning activities largely influence the air quality in Tanzania.

scholarly journals Carbonaceous components, levoglucosan and inorganic ions in tropical aerosols from Tanzania, East Africa: implication for biomass burning contribution to organic aerosols

2012 ◽  
Vol 12 (11) ◽  
pp. 28661-28703 ◽  
Author(s):  
S. L. Mkoma ◽  
K. Kawamura ◽  
P. Fu
Keyword(s):  
Organic Carbon ◽  
East Africa ◽  
Biomass Burning ◽  
Inorganic Ions ◽  
Ionic Species ◽  
Water Soluble ◽  
Total Carbon ◽  
Rural Site ◽  
Wet Season ◽  
Pm2.5 And Pm10

Abstract. Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania in 2011 during wet and dry seasons and they were analysed for carbonaceous components, levoglucosan and water-soluble inorganic ions. The mean mass concentrations of PM2.5 and PM10 were 28.2±6.4 μg m−3 and 47±8.2 μg m−3 in wet season, and 39.1±9.8 μg m−3 and 61.4±19.2 μg m−3 in dry season, respectively. Total carbon (TC) accounted for 16–19% of the PM2.5 mass and 13–15% of the PM10 mass. On average, 85.9 to 88.7% of TC in PM2.5 and 87.2 to 90.1% in PM10 was organic carbon (OC), of which 67–72% and 63% was found to be water-soluble organic carbon (WSOC) in PM2.5 and PM10, respectively. Water-soluble potassium (K+) and sulphate (SO42−) in PM2.5 and, sodium (Na+) and SO42− in PM10 were the dominant ionic species. We found, that concentrations of biomass burning tracers (levoglucosan and mannosan) well correlated with non-sea-salt-K+, WSOC and OC in the aerosols from Tanzania, East Africa. Mean contributions of levoglucosan to OC ranged between 3.9–4.2% for PM2.5 and 3.5–3.8% for PM10. This study demonstrates that emissions from biomass- and biofuel-burning activities followed by atmospheric photochemical processes mainly control the air quality in Tanzania.

scholarly journals Size-resolved measurements of brown carbon and estimates of their contribution to ambient fine particle light absorption based on water and methanol extracts

2013 ◽  
Vol 13 (7) ◽  
pp. 18233-18276 ◽  
Author(s):  
J. Liu ◽  
M. Bergin ◽  
H. Guo ◽  
L. King ◽  
N. Kotra ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Light Absorption ◽  
Fine Particle ◽  
Elemental Carbon ◽  
Fine Particles ◽  
Water Soluble ◽  
Rural Site ◽  
Brown Carbon ◽  
Methanol Extracts ◽  
Carbon Absorption

Abstract. Light absorbing organic carbon, often termed brown carbon, has the potential to significantly contribute to the visible light absorption budget, particularly at shorter wavelengths. Currently, the relative contributions of particulate brown carbon to light absorption, as well as the sources of brown carbon are poorly understood. With this in mind field measurements were made at both urban (Atlanta), and rural (Yorkville) sites in Georgia. Measurements in Atlanta were made at both a central site and a road side site adjacent to a main highway near the city center. Fine particle brown carbon optical absorption is estimated based on Mie calculations using direct size resolved measurements of chromophores in filter extracts. Size-resolved atmospheric aerosol samples were collected using a cascade impactor and analyzed for water-soluble organic carbon (WSOC), organic and elemental carbon (OC and EC), and solution light absorption spectra of water and methanol extracts. Methanol extracts were more light-absorbing than water extracts for all size ranges and wavelengths. Absorption refractive indices of the organic extracts were calculated from solution measurements for a range of wavelengths and used with Mie theory to predict the light absorption by fine particles comprised of these components, under the assumption that brown carbon and other aerosol components were externally mixed. For all three sites, chromophores were predominately in the accumulation mode with an aerodynamic mean diameter of 0.5 μm, an optically effective size range resulting in predicted particle light absorption being a factor of 2 higher than bulk solution absorption. Fine particle absorption was also measured with a Multi-Angle Absorption Photometer (MAAP) and seven-wavelength Aethalometer. Scattering-corrected aethalometer and MAAP absorption were in good agreement at 670 nm and Mie-estimated absorption based on size-resolved EC data were within 30% of these optical instruments. When applied to solution measurements, at all sites, Mie-predicted brown carbon absorption at 350 nm contributed a significant fraction (20 to 40%) relative to total light absorption, with highest contributions at the rural site where organic to elemental carbon ratios were highest. Brown carbon absorption, however, was highest by the roadside site due to vehicle emissions. The multi-wavelength aethalometer did not detect brown carbon, having an absorption Ångstrom exponent near one. Although the results are within the estimated Aethalometer uncertainties, the direct measurement of brown carbon in solution definitively shows that it is present and this Mie analysis suggests it is optically important in the near UV range in both a rural and urban environment during summer when biomass burning emissions are low.

scholarly journals Source Apportionment of Aerosols by 14C Measurements in Different Carbonaceous Particle Fractions

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 475-484 ◽  
Author(s):  
S Szidat ◽  
T M Jenk ◽  
H W Gäggeler ◽  
H-A Synal ◽  
R Fisseha ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Source Apportionment ◽  
Atmospheric Aerosols ◽  
Elemental Carbon ◽  
Water Soluble ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Ambient Aerosols ◽  
Carbonaceous Particle ◽  
Fossil Carbon

Radiocarbon enables a distinction between contemporary and fossil carbon, which can be used for the apportionment of biogenic and anthropogenic sources in environmental studies. In order to apply this approach to carbonaceous atmospheric aerosols, it is necessary to adapt pretreatment procedures to the requirements of 14C measurements. In this work, we followed an approach in which total carbon (TC) is subdivided into fractions of different chemical and physical properties. 14C data of ambient aerosols from Zürich (Switzerland) are presented for the 2 sub-fractions of TC, organic carbon (OC) and elemental carbon (EC). Furthermore, OC is separated into water-insoluble OC (WINSOC) and water-soluble OC (WSOC). Results demonstrate the importance to differentiate between these fractions for 14C-deduced source apportionment, as the contributions can range between both extremes, nearly exclusively biogenic and anthropogenic.

scholarly journals Variability of organic and elemental carbon, water soluble organic carbon, and isotopes in Hong Kong

2006 ◽  
Vol 6 (12) ◽  
pp. 4569-4576 ◽  
Author(s):  
K. F. Ho ◽  
S. C. Lee ◽  
J. J. Cao ◽  
Y. S. Li ◽  
J. C. Chow ◽  
...  
Keyword(s):  
Hong Kong ◽  
Organic Carbon ◽  
Elemental Carbon ◽  
Motor Vehicle ◽  
Regional Scale ◽  
Water Soluble ◽  
Total Carbon ◽  
Carbonaceous Aerosol ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon

Abstract. To determine the levels and variations of carbonaceous aerosol in Hong Kong, PM2.5 and PM10 samples were collected by high volume (Hi-vol) samplers at three monitoring stations (representing middle-scale roadside, urban-, and regional-scale environments) during winter (November 2000 to February 2001) and summer (June 2001 to August 2001) periods. The highest concentrations of organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were found at the middle-scale roadside site with the lowest at the regional-scale site. The percentages of WSOC in total carbon at these sites were inversely correlated with their concentrations (i.e., the highest percentages of WSOC were observed at the regional-scale site). A high WSOC fraction may be associated with aged aerosol because of the secondary formation by photochemical oxidation of organic precursors of anthropogenic pollutants during transport. The annual average of isotope abundances (δ13C) of OC and EC were –26.9±0.5‰ and –25.6±0.1‰, respectively. There were no notable differences for seasonal distributions of carbon isotopic composition, consistent with motor vehicle emissions being the main source contributors of carbonaceous aerosol in Hong Kong. OC 13C abundances at the regional-scale site were higher than those at the middle-scale roadside and urban sites, consistent with secondary organic aerosols of biogenic origin.

scholarly journals Variability of organic and elemental carbon, water soluble organic carbon, and isotopes in Hong Kong

2006 ◽  
Vol 6 (3) ◽  
pp. 4579-4600 ◽  
Author(s):  
K. F. Ho ◽  
S. C. Lee ◽  
J. J. Cao ◽  
Y. S. Li ◽  
J. C. Chow ◽  
...  
Keyword(s):  
Hong Kong ◽  
Organic Carbon ◽  
Elemental Carbon ◽  
Motor Vehicle ◽  
Regional Scale ◽  
Water Soluble ◽  
Total Carbon ◽  
Carbonaceous Aerosol ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon

Abstract. To determine the levels and variations of carbonaceous aerosol in Hong Kong, PM2.5 and PM10 samples were collected by high volume (Hi-vol) samplers at three monitoring stations (representing middle-scale roadside, urban-, and regional-scale environments) during winter (November 2000 to February 2001) and summer (June 2001 to August 2001) periods. The highest concentrations of organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were found at the middle-scale roadside site with the lowest at the regional-scale site. The percentages of WSOC in total carbon at these sites were inversely correlated with their concentrations (i.e., the highest percentages of WSOC were observed at the regional-scale site). A high WSOC fraction may be associated with aged aerosol because of the secondary formation by photochemical oxidation of organic precursors of anthropogenic pollutants during transport. The annual average of isotope abundances (δ13C) of OC and EC were –26.9±0.5 and –25.6±0.1, respectively. There were no notable differences for seasonal distributions of carbon isotopic composition, consistent with motor vehicle emissions being the main source contributors of carbonaceous aerosol in Hong Kong. OC 13C abundances at the regional-scale site were higher than those at the middle-scale roadside and urban sites, consistent with secondary organic aerosols of biogenic origin.

scholarly journals Size-resolved measurements of brown carbon in water and methanol extracts and estimates of their contribution to ambient fine-particle light absorption

2013 ◽  
Vol 13 (24) ◽  
pp. 12389-12404 ◽  
Author(s):  
J. Liu ◽  
M. Bergin ◽  
H. Guo ◽  
L. King ◽  
N. Kotra ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Light Absorption ◽  
Fine Particle ◽  
Elemental Carbon ◽  
Rural Site ◽  
Urban Site ◽  
Brown Carbon ◽  
Methanol Extracts ◽  
Direct Measurements ◽  
Carbon Absorption

Abstract. Light absorbing organic carbon, often called brown carbon, has the potential to significantly contribute to the visible light-absorption budget, particularly at shorter wavelengths. Currently, the relative contributions of particulate brown carbon to light absorption, as well as the sources of brown carbon, are poorly understood. With this in mind size-resolved direct measurements of brown carbon were made at both urban (Atlanta), and rural (Yorkville) sites in Georgia. Measurements in Atlanta were made at both a representative urban site and a road-side site adjacent to a main highway. Fine particle absorption was measured with a multi-angle absorption photometer (MAAP) and seven-wavelength Aethalometer, and brown carbon absorption was estimated based on Mie calculations using direct size-resolved measurements of chromophores in solvents. Size-resolved samples were collected using a cascade impactor and analyzed for water-soluble organic carbon (WSOC), organic and elemental carbon (OC and EC), and solution light-absorption spectra of water and methanol extracts. Methanol extracts were more light-absorbing than water extracts for all size ranges and wavelengths. Absorption refractive indices of the organic extracts were calculated from solution measurements for a range of wavelengths and used with Mie theory to predict the light absorption by fine particles comprised of these components, under the assumption that brown carbon and other aerosol components were externally mixed. For all three sites, chromophores were predominately in the accumulation mode with an aerodynamic mean diameter of 0.5 μm, an optically effective size range resulting in predicted particle light absorption being a factor of 2 higher than bulk solution absorption. Mie-predicted brown carbon absorption at 350 nm contributed a significant fraction (20 to 40%) relative to total light absorption, with the highest contributions at the rural site where organic to elemental carbon ratios were highest. Brown carbon absorption, however, was highest by the roadside site due to vehicle emissions. The direct size-resolved measurement of brown carbon in solution definitively shows that it is present and optically important in the near-UV range in both a rural and urban environment during the summer when biomass burning emissions are low. These results allow estimates of brown carbon aerosol absorption from direct measurements of chromophores in aerosol extracts.

scholarly journals Spatio-Temporal Variation of Atmospheric Gaseous and Particulate Reactive Nitrogen over Northern India

2021 ◽  
Vol Special Issue (1) ◽  
pp. 53-67
Author(s):  
Manisha Mishra ◽  
Umesh C Kulshrestha
Keyword(s):  
Source Parameters ◽  
Ambient Air ◽  
Water Soluble ◽  
Rural Site ◽  
Urban Site ◽  
Local Source ◽  
Reactive Nitrogen ◽  
Gangetic Plain ◽  
Reactive N ◽  
Spatio Temporal

The present study reports spatio-temporal distribution pattern of major gaseous (NH3 and NO2) and particulate water soluble total nitrogen (pWSTN) in the ambient air to explore the seasonal variation, major interactions and dominating sources. Considering the major hotspot of atmospheric reactive nitrogen (N) emission, three sites in Indo-Gangetic plain (IGP) were selected based on different local source parameters. Results have shown that gas phase reactive N contribute up to 90% of total analyzed reactive N, where NH3 imparted highest at all the three sites. Prayagraj, a fast growing urban site, has shown highest concentrations of NH3 (72.0 μg m−3), followed by Madhupur rural site (57.7 μg m−3) and Delhi, an urban megacity site (35.8 μg m−3). As compared to previous studies conducted at different sites of IGP, NH3 concentrations were reported to be the highest at the former two sites. However, unlike NH3, NO2 levels were recorded lower at Madhupur (3.1 μg m−3) and Prayagraj (9.4 μg m−3) sites as compared to Delhi (13.4 μg m−3). Similarly, pWSTN concentrations were in the order of Madhupur (6.6 μg m−3) < Prayagraj (10.0 μg m−3) < Delhi (10.1 μg m−3). A strong correlation of NO2 with pWSTN at urban sites has shown the crucial role of NO2 in the formation of nitrogenous aerosols. Significant spatial variation can be attributed to varying local emission sources ranging from microbial emission from improper sewage treatment and open waste dumping at Prayagraj, agricultural activities at Madhupur and vehicular exhausts at Delhi site.

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