Supplementary material to "Long-term Brown Carbon and Smoke Tracer Observations in Bogotá, Colombia: Association to Medium-Range Transport of Biomass Burning Plumes"

Abstract. Organic aerosol (OA) particles are recognized as key factors influencing air quality and climate change. However, highly time-resolved long-term characterizations of their composition and sources in ambient air are still very limited due to challenging continuous observations. Here, we present an analysis of long-term variability of submicron OA using the combination of an aerosol chemical speciation monitor (ACSM) and a multiwavelength Aethalometer from November 2011 to March 2018 at a peri-urban background site of the Paris region (France). Source apportionment of OA was achieved via partially constrained positive matrix factorization (PMF) using the multilinear engine (ME-2). Two primary OA (POA) and two oxygenated OA (OOA) factors were identified and quantified over the entire studied period. POA factors were designated as hydrocarbon-like OA (HOA) and biomass burning OA (BBOA). The latter factor presented a significant seasonality with higher concentrations in winter with significant monthly contributions to OA (18 %–33 %) due to enhanced residential wood burning emissions. HOA mainly originated from traffic emissions but was also influenced by biomass burning in cold periods. OOA factors were distinguished between their less- and more-oxidized fractions (LO-OOA and MO-OOA, respectively). These factors presented distinct seasonal patterns, associated with different atmospheric formation pathways. A pronounced increase in LO-OOA concentrations and contributions (50 %–66 %) was observed in summer, which may be mainly explained by secondary OA (SOA) formation processes involving biogenic gaseous precursors. Conversely, high concentrations and OA contributions (32 %–62 %) of MO-OOA during winter and spring seasons were partly associated with anthropogenic emissions and/or long-range transport from northeastern Europe. The contribution of the different OA factors as a function of OA mass loading highlighted the dominant roles of POA during pollution episodes in fall and winter and of SOA for highest springtime and summertime OA concentrations. Finally, long-term trend analyses indicated a decreasing feature (of about −175 ng m−3 yr−1) for MO-OOA, very limited or insignificant decreasing trends for primary anthropogenic carbonaceous aerosols (BBOA and HOA, along with the fossil-fuel and biomass-burning black carbon components) and no statistically significant trend for LO-OOA over the 6-year investigated period.

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Record high peaks in PCB concentrations in the Arctic atmosphere due to long-range transport of biomass burning emissions

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-4527-2007 ◽

2007 ◽

Vol 7 (17) ◽

pp. 4527-4536 ◽

Cited By ~ 74

Author(s):

S. Eckhardt ◽

K. Breivik ◽

S. Manø ◽

A. Stohl

Keyword(s):

Biomass Burning ◽

Dry Matter ◽

The Arctic ◽

Pcb Congeners ◽

Range Transport ◽

Standard Deviations ◽

High Concentrations ◽

Arctic Atmosphere ◽

Primary Emissions

Abstract. Soils and forests in the boreal region of the Northern Hemisphere are recognised as having a large capacity for storing air-borne Persistent Organic Pollutants (POPs), such as the polychlorinated biphenyls (PCBs). Following reductions of primary emissions of various legacy POPs, there is an increasing interest and debate about the relative importance of secondary re-emissions on the atmospheric levels of POPs. In spring of 2006, biomass burning emissions from agricultural fires in Eastern Europe were transported to the Zeppelin station on Svalbard, where record-high levels of many air pollutants were recorded (Stohl et al., 2007). Here we report on the extremely high concentrations of PCBs that were also measured during this period. 21 out of 32 PCB congeners were enhanced by more than two standard deviations above the long-term mean concentrations. In July 2004, about 5.8 million hectare of boreal forest burned in North America, emitting a pollution plume which reached the Zeppelin station after a travel time of 3–4 weeks (Stohl et al., 2006). Again, 12 PCB congeners were elevated above the long-term mean by more than two standard deviations, with the less chlorinated congeners being most strongly affected. We propose that these abnormally high concentrations were caused by biomass burning emissions. Based on enhancement ratios with carbon monoxide and known emissions factors for this species, we estimate that 130 and 66 μg PCBs were released per kilogram dry matter burned, respectively. To our knowledge, this is the first study relating atmospheric PCB enhancements with biomass burning. The strong effects on observed concentrations far away from the sources, suggest that biomass burning is an important source of PCBs for the atmosphere.

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Long-term measurements of carbonaceous aerosols in the Eastern Mediterranean: evidence of long-range transport of biomass burning

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-5551-2008 ◽

2008 ◽

Vol 8 (18) ◽

pp. 5551-5563 ◽

Cited By ~ 126

Author(s):

J. Sciare ◽

K. Oikonomou ◽

O. Favez ◽

E. Liakakou ◽

Z. Markaki ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Long Range ◽

Biomass Burning ◽

Water Soluble ◽

Long Range Transport ◽

Crete Island ◽

Yearly Average ◽

Range Transport

Abstract. Long-term (5-year) measurements of Elemental Carbon (EC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these EC and OC measurements. Light absorbing dust aerosols were shown to poorly contribute (+12% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical method (aethalometer). Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March–April and July–September). The contribution of biomass burning to the concentrations of EC and OC was shown to be rather small (20 and 14%, respectively, on a yearly basis), although this contribution could be much higher on a monthly basis and showed important seasonal and interannual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC) have shown that the monthly mean WSOC/OC ratio remains stable throughout the year (0.45±0.12), suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA) formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A.D.<1.5μm) showed that the mass contribution of organic matter (POM) was found to be essentially invariable during the year (monthly average of 26±5%).

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Record high peaks in PCB concentrations in the Arctic atmosphere due to long-range transport of biomass burning emissions

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-6229-2007 ◽

2007 ◽

Vol 7 (3) ◽

pp. 6229-6254 ◽

Cited By ~ 2

Author(s):

S. Eckhardt ◽

K. Breivik ◽

S. Man\\o ◽

A. Stohl

Keyword(s):

Biomass Burning ◽

Dry Matter ◽

The Arctic ◽

Pcb Congeners ◽

Range Transport ◽

Standard Deviations ◽

High Concentrations ◽

Arctic Atmosphere ◽

Primary Emissions

Abstract. Soils and forests in the boreal region of the northern hemisphere are recognised as having a large capacity for storing air-borne Persistent Organic Pollutants (POPs), such as the polychlorinated biphenyls (PCBs). Following reductions of primary emissions of various legacy POPs, there is an increasing interest and debate about the relative importance of secondary re-emissions on the atmospheric levels of POPs. In spring of 2006, biomass burning emissions from agricultural fires in Eastern Europe were transported to the Zeppelin station on Svalbard, where record-high levels of many air pollutants were recorded (Stohl et al., 2007). Here we report on the extremely high concentrations of PCBs that were also measured during this period. 21 out of 32 PCB congeners were enhanced by more than two standard deviations above the long-term mean concentrations. In July 2004, about 5.8 million hectare of boreal forest burned in North America, emitting a pollution plume which reached the Zeppelin station after a travel time of 3–4 weeks (Stohl et al., 2006). Again, 12 PCB congeners were elevated above the long-term mean by more than two standard deviations, with the less chlorinated congeners being most strongly affected. We propose that these abnormally high concentrations were caused by biomass burning emissions. Based on enhancement ratios with carbon monoxide and known emissions factors for this species, we estimate that 130 and 66 μg PCBs were released per kilogram dry matter burned, respectively. To our knowledge, this is the first study relating atmospheric PCB enhancements with biomass burning. The strong effects on observed concentrations far away from the sources, suggest that biomass burning is an important source of PCBs for the atmosphere.

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Long-term measurements of carbonaceous aerosols in the eastern Mediterranean: evidence of long-range transport of biomass burning

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-6949-2008 ◽

2008 ◽

Vol 8 (2) ◽

pp. 6949-6982 ◽

Cited By ~ 4

Author(s):

J. Sciare ◽

K. Oikonomou ◽

O. Favez ◽

Z. Markaki ◽

E. Liakakou ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Long Range ◽

Biomass Burning ◽

Water Soluble ◽

Long Range Transport ◽

Crete Island ◽

Yearly Average ◽

Range Transport

Abstract. Long-term (5-yr) measurements of Black Carbon (BC) and Organic Carbon (OC) in bulk aerosols are presented here for the first time in the Mediterranean Basin (Crete Island). A multi-analytical approach (including thermal, optical, and thermo-optical techniques) was applied for these BC and OC measurements. Light absorbing dust aerosols have shown to poorly contribute (+17% on a yearly average) to light absorption coefficient (babs) measurements performed by an optical method (aethalometer). Long-range transport of agricultural waste burning from European countries surrounding the Black Sea was shown for each year during two periods (March–April and July–September). The contribution of biomass burning to the concentrations of BC and OC has shown to be rather small (20 and 14%, respectively, on a yearly basis), although this contribution could be much higher on a monthly basis and is expected a high intra and inter annual variability. By removing the biomass burning influence, our data revealed an important seasonal variation of OC, with an increase by almost a factor of two for the Spring months of May and June, whereas BC was found to be quite stable throughout the year. Preliminary measurements of Water Soluble Organic Carbon (WSOC) have shown that the monthly mean WSOC/OC ratio remains stable throughout the year (0.45±0.12), suggesting that the partitioning between water soluble and water insoluble organic matter is not significantly affected by biomass burning and secondary organic aerosol (SOA) formation. A chemical mass closure performed in the fine mode (Aerodynamic Diameter, A.D.<1.5 μm) showed that the mass contribution of organic matter (POM) was found to be essentially invariable during the year (monthly average of 26±5%).

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Light absorption of brown carbon in eastern China based on 3-year multi-wavelength aerosol optical property observations at the SORPES station and an improved Absorption Ångstrom exponent segregation method

10.5194/acp-2018-49 ◽

2018 ◽

Author(s):

Jiaping Wang ◽

Wei Nie ◽

Yafang Cheng ◽

Yicheng Shen ◽

Xuguang Chi ◽

...

Keyword(s):

Biomass Burning ◽

Light Absorption ◽

Mie Theory ◽

Brown Carbon ◽

Angstrom Exponent ◽

Lagrangian Modeling ◽

Ångström Exponent ◽

Multi Wavelength ◽

Ångstrom Exponent

Abstract. Brown carbon (BrC), a certain group of organic carbon (OC) with strong absorption from the visible to ultraviolet (UV) wavelengths, makes considerable contribution to light absorption on both global and regional scales. High concentration and proportion of OC has been reported in China, but studies of BrC absorption based on long-term observations are rather limited in this region. In this study, we reported 3-year results of light absorption of BrC based on continuous measurement at the Station for Observation Regional Processes of the Earth System (SORPES) in the Yangtze River Delta, China combined with Mie-theory calculation. Light absorption of BrC was obtained using an improved Absorption Ångstrom exponent (AAE) segregation method to calculate AAE of pure and non-absorbing coated black carbon (BC) at each time step based on Mie-theory simulation and measurement of multi-wavelength aerosol light absorption. By using this improved method, the variation of AAE over time is taken into consideration, making it applicable for long-term analysis. The yearly average light absorption of BrC (babs_BrC) at 370 nm was 4.3 Mm−1 at the SORPES station. The contribution of BrC to total aerosol absorption (PBrC) at 370 nm ranged from 6 % to 18 % (10th and 90th percentiles, respectively), and reached up to ~ 28 % in biomass burning-dominant season and winter. Both babs_BrC and PBrC exhibited clear seasonal cycles with two peaks in later spring/early summer (May–June, babs_BrC ~ 4 Mm−1, PBrC ~ 11 %) and winter (December, babs_BrC ~ 12 Mm−1, PBrC ~ 17 %), respectively. Lagrangian modeling and chemical signature observed at the site suggested that open biomass burning and residential emissions were the dominate sources influencing BrC in the two seasons.

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Light absorption of brown carbon in eastern China based on 3-year multi-wavelength aerosol optical property observations and an improved absorption Ångström exponent segregation method

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-9061-2018 ◽

2018 ◽

Vol 18 (12) ◽

pp. 9061-9074 ◽

Cited By ~ 20

Author(s):

Jiaping Wang ◽

Wei Nie ◽

Yafang Cheng ◽

Yicheng Shen ◽

Xuguang Chi ◽

...

Keyword(s):

Biomass Burning ◽

Light Absorption ◽

Mie Theory ◽

Time Step ◽

Brown Carbon ◽

Angstrom Exponent ◽

Lagrangian Modeling ◽

Ångström Exponent ◽

Ångstrom Exponent

Abstract. Brown carbon (BrC), a certain group of organic carbon (OC) with strong absorption from the visible (VIS) to ultraviolet (UV) wavelengths, makes a considerable contribution to light absorption on both global and regional scales. A high concentration and proportion of OC has been reported in China, but studies of BrC absorption based on long-term observations are rather limited in this region. In this study, we reported 3-year results of light absorption of BrC based on continuous measurement at the Station for Observing Regional Processes of the Earth System (SORPES) in the Yangtze River Delta, China, combined with Mie theory calculation. Light absorption of BrC was obtained using an improved absorption Ångström exponent (AAE) segregation method. The AAE of non-absorbing coated black carbon (BC) at each time step is calculated based on Mie theory simulation, together with single particle soot photometer (SP2) and aethalometer observations. By using this improved method, the variation of the AAE over time is taken into consideration, making it applicable for long-term analysis. The annual average light absorption coefficient of BrC (babs_BrC) at 370 nm was 6.3 Mm−1 at the SORPES station. The contribution of BrC to total aerosol absorption (PBrC) at 370 nm ranged from 10.4 to 23.9 % (10th and 90th percentiles, respectively), and reached up to ∼ 33 % in the open-biomass-burning-dominant season and winter. Both babs_BrC and PBrC exhibited clear seasonal cycles with two peaks in later spring/early summer (May–June, babs_BrC ∼ 6 Mm−1, PBrC ∼ 17 %) and winter (December, babs_BrC ∼ 15 Mm−1, PBrC ∼ 22 %), respectively. Lagrangian modeling and the chemical signature observed at the site suggested that open biomass burning and residential coal/biofuel burning were the dominant sources influencing BrC in the two seasons, respectively.

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Supplementary material to "Atmospheric Evolution of Molecular Weight Separated Brown Carbon from Biomass Burning"

10.5194/acp-2018-903-supplement ◽

2018 ◽

Author(s):

Jenny P. S. Wong ◽

Maria Tsagaraki ◽

Irini Tsiodra ◽

Nikolaos Mihalopoulos ◽

Kalliopi Violaki ◽

...

Keyword(s):

Molecular Weight ◽

Biomass Burning ◽

Brown Carbon ◽

Atmospheric Evolution ◽

Supplementary Material

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