scholarly journals Source apportionment of black carbon aerosols from light absorption observation and source-oriented modeling: an implication in a coastal city in China

2020 ◽  
Vol 20 (22) ◽  
pp. 14419-14435
Author(s):  
Junjun Deng ◽  
Hao Guo ◽  
Hongliang Zhang ◽  
Jialei Zhu ◽  
Xin Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Black Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Light Absorption ◽  
Fossil Fuel ◽  
Central China ◽  
Fossil Fuel Combustion ◽  
East Central ◽  
Coastal City

Abstract. Black carbon (BC) is the most important light-absorbing aerosol in the atmosphere. However, sources of atmospheric BC aerosols are largely uncertain, making it difficult to assess its influence on radiative forcing and climate change. In this study, year-round light-absorption observations were conducted during 2014 using an aethalometer in Xiamen, a coastal city in Southeast China. Source apportionment of BC was performed and temporal variations in BC sources were characterized based on both light absorption measurements and a source-oriented air quality model. The annual average concentrations of BC from fossil fuel (BCff) and biomass burning (BCbb) by the aethalometer method were 2932 ± 1444 ng m−3 and 1340 ± 542 ng m−3, contributing 66.7 % and 33.3 % to total BC, respectively. A sensitivity analysis was performed with different absorption Ångström exponent (AAE) values of fossil fuel combustion (αff) and biomass burning (αbb), suggesting that the aethalometer method was more sensitive to changes in αbb than αff. BCbb contribution exhibited a clear diurnal cycle, with the highest level (37.9 %) in the evening rush hour and a seasonal pattern with the maximum (39.9 %) in winter. Conditional probability function (CPF) analysis revealed the large biomass-burning contributions were accompanied by east-northeasterly and northerly winds. Backward trajectory indicated that air masses from North and East–Central China were associated with larger biomass-burning contributions. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) suggested that North and East–Central China and Southeast Asia were potential sources of both BCff and BCbb. The source-oriented modeling results showed that transportation, residential and open biomass burning accounting for 45.3 %, 30.1 % and 17.6 % were the major BC sources. Among the three fuel catalogs, liquid fossil fuel (46.5 %) was the largest source, followed by biomass burning (32.6 %) and coal combustion (20.9 %). Source contributions of fossil fuel combustion and biomass burning identified by the source-oriented model were 67.4 % and 32.6 %, respectively, close to those obtained by the aethalometer method. The findings provide solid support for controlling fossil fuel sources to limit the impacts of BC on climate change and environmental degradation in the relatively clean region in China.

scholarly journals Source apportionment of black carbon aerosols from light absorption observation and source-oriented modeling: An implication in a coastal city in China

2020 ◽  
Author(s):  
Junjun Deng ◽  
Hao Guo ◽  
Hongliang Zhang ◽  
Jialei Zhu ◽  
Xin Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Black Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Light Absorption ◽  
Fossil Fuel ◽  
Central China ◽  
East Central ◽  
Coastal City ◽  
Source Contributions

Abstract. Black carbon (BC) is the most important light absorbing aerosol in the atmosphere. However, sources of atmospheric BC aerosols are largely uncertain, making it difficult to assess its influence on radiative forcing and climate change. In this study, year-round light-absorption observations were conducted during 2014 using an aethalometer in Xiamen, a coastal city in southeast China. Source apportionment of BC was performed and temporal variations in BC sources were characterized based on both light absorption measurements and a source-oriented air quality model. The annual average concentrations of BC from fossil fuel (BCff) and biomass burning (BCbb) were 2932 ± 1444 ng m−3 and 1340 ± 542 ng m−3, contributing 66.7 % and 33.3 % to total BC, respectively. BCbb contribution exhibited clear diurnal cycle with the highest level (37.9 %) in the evening rush hour and seasonal pattern with the maximum (39.9 %) in winter. Conditional probability function (CPF) analysis revealed the large biomass burning contributions were accompanied by east-northeasterly and northerly winds. Backward trajectory indicated that air masses from north and east-central China were associated with larger biomass burning contributions. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) suggested that north and east-central China and Southeast Asia were potential sources for both BCff and BCbb. The source-oriented modeling results showed that transportation, residential and open biomass burning accounting for 45.3 %, 30.1 % and 17.6 % were the major BC sources. Among the three fuel catalogs, liquid fossil fuel (46.5 %) was the largest source, followed by biomass burning (32.6 %) and coal combustion (20.9 %). Source contributions of biomass burning and fossil fuel combustion identified by the source-oriented model and observation-based method were in good agreement. The source-oriented model also captured the majority of seasonal variations in source contributions. The findings provide solid supports for controlling fossil fuel sources to limit the impacts of BC on climate change and environmental degradation in the relatively clean region in China.

Source apportionment of black carbon (BC) from fossil fuel and biomass burning in metropolitan Milan, Italy

2019 ◽  
Vol 203 ◽  
pp. 252-261 ◽  
Author(s):  
Amirhosein Mousavi ◽  
Mohammad H. Sowlat ◽  
Christopher Lovett ◽  
Martin Rauber ◽  
Soenke Szidat ◽  
...  
Keyword(s):  
Black Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Fossil Fuel

Spatio-temporal trends and source apportionment of fossil fuel and biomass burning black carbon (BC) in the Los Angeles Basin

2018 ◽  
Vol 640-641 ◽  
pp. 1231-1240 ◽  
Author(s):  
Amirhosein Mousavi ◽  
Mohammad H. Sowlat ◽  
Sina Hasheminassab ◽  
Andrea Polidori ◽  
Constantinos Sioutas
Keyword(s):  
Los Angeles ◽  
Black Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Fossil Fuel ◽  
Temporal Trends ◽  
Los Angeles Basin ◽  
Spatio Temporal

Ambient measurements and source apportionment of fossil fuel and biomass burning black carbon in Ontario

2017 ◽  
Vol 161 ◽  
pp. 34-47 ◽  
Author(s):  
R.M. Healy ◽  
U. Sofowote ◽  
Y. Su ◽  
J. Debosz ◽  
M. Noble ◽  
...  
Keyword(s):  
Black Carbon ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Fossil Fuel ◽  
Ambient Measurements

scholarly journals Fossil fuel combustion and biomass burning sources of global black carbon from GEOS-Chem simulation and carbon isotope measurements

2019 ◽  
Vol 19 (17) ◽  
pp. 11545-11557 ◽  
Author(s):  
Ling Qi ◽  
Shuxiao Wang
Keyword(s):  
Black Carbon ◽  
Carbon Isotope ◽  
Biomass Burning ◽  
Fossil Fuel ◽  
Transport Model ◽  
Fuel Combustion ◽  
The Arctic ◽  
Fossil Fuel Combustion ◽  
The Antarctic ◽  
Isotope Measurements

Abstract. We identify sources (fossil fuel combustion versus biomass burning) of black carbon (BC) in the atmosphere and in deposition using a global 3-D chemical transport model GEOS-Chem. We validate the simulated sources against carbon isotope measurements of BC around the globe and find that the model reproduces mean biomass burning contribution (fbb; %) in various regions within a factor of 2 (except in Europe, where fbb is underestimated by 63 %). GEOS-Chem shows that contribution from biomass burning in the Northern Hemisphere (fbb: 35±14 %) is much less than that in the Southern Hemisphere (50±11 %). The largest atmospheric fbb is in Africa (64±20 %). Comparable contributions from biomass burning and fossil fuel combustion are found in southern (S) Asia (53±10 %), southeastern (SE) Asia (53±11 %), S America (47±14 %), the S Pacific (47±7 %), Australia (53±14 %) and the Antarctic (51±2 %). fbb is relatively small in eastern Asia (40±13 %), Siberia (35±8 %), the Arctic (33±6 %), Canada (31±7 %), the US (25±4 %) and Europe (19±7 %). Both observations and model results suggest that atmospheric fbb is higher in summer (59 %–78 %, varying with sub-regions) than in winter (28 %–32 %) in the Arctic, while it is higher in winter (42 %–58 %) and lower in summer (16 %–42 %) over the Himalayan–Tibetan Plateau. The seasonal variations of Atmosphericfbb are relatively flat in North America, Europe and Asia. We conducted four experiments to investigate the uncertainties associated with biofuel emissions, hygroscopicity of BC in fresh emissions, the aging rate and size-resolved wet scavenging. We find that doubling biofuel emissions for domestic heating north of 45∘ N increases fbb values in Europe in winter by ∼30 %, reducing the discrepancy between observed and modeled atmospheric fbb from −63 % to −54 %. The remaining large negative discrepancy between model and observations suggests that the biofuel emissions are probably still underestimated at high latitudes. Increasing the fraction of thickly coated hydrophilic BC from 20 % to 70 % in fresh biomass burning plumes increases the fraction of hydrophilic BC in biomass burning plumes by 0 %–20 % (varying with seasons and regions) and thereby reduces atmospheric fbb by up to 11 %. Faster aging (4 h e-folding time versus 1.15 d e-folding time) of BC in biomass burning plumes reduces atmospheric fbb by 7 % (1 %–14 %, varying with seasons and regions), with the largest reduction in remote regions, such as the Arctic, the Antarctic and the S Pacific. Using size-resolved scavenging accelerates scavenging of BC particles in both fossil fuel and biomass burning plumes, with a faster scavenging of BC in fossil fuel plumes. Thus, atmospheric fbb increases in most regions by 1 %–14 %. Overall, atmospheric fbb is determined mainly by fbb in emissions and, to a lesser extent, by atmospheric processes, such as aging and scavenging. This confirms the assumption that fbb in local emissions determines atmospheric fbb in previous studies, which compared measured atmospheric fbb directly with local fbb in bottom-up emission inventories.

scholarly journals A 2.5 year's source apportionment study of black carbon from wood burning and fossil fuel combustion at urban and rural sites in Switzerland

2011 ◽  
Vol 4 (7) ◽  
pp. 1409-1420 ◽  
Author(s):  
H. Herich ◽  
C. Hueglin ◽  
B. Buchmann
Keyword(s):  
Black Carbon ◽  
Source Apportionment ◽  
Cross Sections ◽  
Light Absorption ◽  
Fossil Fuel ◽  
Data Sets ◽  
Near Ultraviolet ◽  
Wood Burning ◽  
Multi Wavelength ◽  
Rural Sites

Abstract. The contributions of fossil fuel (FF) and wood burning (WB) emissions to black carbon (BC) have been investigated in the recent past by analysis of multi-wavelength aethalometer data. This approach utilizes the stronger light absorption of WB aerosols in the near ultraviolet compared to the light absorption of aerosols from FF combustion. Here we present 2.5 years of seven-wavelength aethalometer data from one urban and two rural background sites in Switzerland measured from 2008–2010. The contribution of WB and FF to BC was directly determined from the aerosol absorption coefficients of FF and WB aerosols which were calculated by using confirmed Ångstrom exponents and aerosol light absorption cross-sections that were determined for all sites. Reasonable separation of total BC into contributions from FF and WB was achieved for all sites and seasons. The obtained WB contributions to BC are well correlated with measured concentrations of levoglucosan and potassium while FF contributions to BC correlate nicely with NOx. These findings support our approach and show that the applied source apportionment of BC is well applicable for long-term data sets. During winter, we found that BC from WB contributes on average 24–33 % to total BC at the considered measurement sites. This is a noticeable high fraction as the contribution of wood burning to the total final energy consumption is in Switzerland less than 4 %.

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