scholarly journals Refractory black carbon mass concentrations in snow and ice: method evaluation and inter-comparison with elemental carbon measurement

2014 ◽  
Vol 7 (4) ◽  
pp. 3549-3589 ◽  
Author(s):  
S. Lim ◽  
X. Faïn ◽  
M. Zanatta ◽  
J. Cozic ◽  
J.-L. Jaffrezo ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Elemental Carbon ◽  
Data Interpretation ◽  
The Caucasus ◽  
Analytical Technique ◽  
Quartz Fiber Filter ◽  
The Impact ◽  
Mass Concentrations ◽  
Snow And Ice

Abstract. Accurate measurement of black carbon (BC) mass concentrations in snow and ice is crucial for the assessment of climatic impacts. However, it is difficult to compare methods used to assess BC levels in the literature as they are not the same. The single particle soot photometer (SP2) method appears to be one of the most suitable to measure low concentrations of BC in snow and ice. However, deriving BC concentrations with SP2 is not straightforward and different measurement options may lead to different results. In this paper, we propose an optimized method for the quantification of refractory BC (rBC) in snow and ice samples using SP2. The paper reviews all the steps of rBC determination including SP2 calibration, correction for rBC particle aerosolization, and treatment of the samples. In addition, we compare the SP2 method and the thermal-optical method (Sunset organic carbon (OC)-elemental carbon (EC) aerosol analyzer with EUSAAR-2 protocol), using snow and firn samples with different characteristics from the Greenland Summit, the French Alps, the Caucasus, and the Himalayas. The EC : rBC ratio was 1.8 ± 1.2 for the Greenland site, 0.4 ± 0.2 for the Alpine site, 0.9 ± 0.3 for the Caucasus site, and 3.0 ± 1.2 for the Himalayan site. Careful investigation was undertaken of analytical uncertainties in both methods, concerning the analytical range of detection of BC, aerosolization correction for rBC, filtration efficiency of quartz fiber filter before EC analysis, the impact of dust, and pyrolyzed organic carbon artifacts during EC analysis. We conclude that the complexity of artifacts can lead to inaccurate rBC or EC determination. In particular, we observed significant under-estimation of EC due to incomplete filtration together with positive artifacts caused by OC. These results underline the need for careful assessment of the analytical technique and procedure for correct data interpretation.

scholarly journals Refractory black carbon mass concentrations in snow and ice: method evaluation and inter-comparison with elemental carbon measurement

2014 ◽  
Vol 7 (10) ◽  
pp. 3307-3324 ◽  
Author(s):  
S. Lim ◽  
X. Faïn ◽  
M. Zanatta ◽  
J. Cozic ◽  
J.-L. Jaffrezo ◽  
...  
Keyword(s):  
Black Carbon ◽  
Elemental Carbon ◽  
Data Interpretation ◽  
Detection Range ◽  
Analytical Technique ◽  
Low Concentrations ◽  
Quartz Fiber Filter ◽  
Carbon Mass ◽  
Mass Concentrations ◽  
Snow And Ice

Abstract. Accurate measurement of black carbon (BC) mass concentrations in snow and ice is crucial for the assessment of climatic impacts. However, it is difficult to compare methods used to assess BC levels in the literature as they are not the same. The single particle soot photometer (SP2) method appears to be one of the most suitable to measure low concentrations of BC in snow and ice. In this paper, we evaluated a method for the quantification of refractory BC (rBC) in snow and ice samples coupling the SP2 with the APEX-Q nebulizer. The paper reviews all the steps of rBC determination, including SP2 calibration, correction for rBC particle aerosolization efficiency (75 ± 7% using the APEX-Q nebulizer), and treatment of the samples. In addition, we compare the SP2 method and the thermal–optical method – Sunset organic carbon (OC) / elemental carbon (EC) aerosol analyzer with EUSAAR2 protocol – using snow and firn samples with different characteristics from the Greenland Summit, the French Alps, the Caucasus, and the Himalayas. Careful investigation was undertaken of analytical artifacts that potentially affect both methods. The SP2-based rBC quantification may be underestimated when the SP2 detection range does not cover correctly the existing size distribution of the sample. Thermal–optical EC measurements can be underestimated by low filtration efficiency of quartz fiber filter before analysis or dust properties (concentration and type), and overestimated by pyrolyzed OC artifacts during EC analysis. These results underline the need for careful assessment of the analytical technique and procedure for correct data interpretation.

scholarly journals A global modeling study on carbonaceous aerosol microphysical characteristics and radiative effects

2010 ◽  
Vol 10 (15) ◽  
pp. 7439-7456 ◽  
Author(s):  
S. E. Bauer ◽  
S. Menon ◽  
D. Koch ◽  
T. C. Bond ◽  
K. Tsigaridis
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Radiative Flux ◽  
Radiative Effects ◽  
Carbonaceous Particle ◽  
Flux Change ◽  
Aerosol Effects ◽  
The Impact ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Abstract. Recently, attention has been drawn towards black carbon aerosols as a short-term climate warming mitigation candidate. However the global and regional impacts of the direct, indirect and semi-direct aerosol effects are highly uncertain, due to the complex nature of aerosol evolution and the way that mixed, aged aerosols interact with clouds and radiation. A detailed aerosol microphysical scheme, MATRIX, embedded within the GISS climate model is used in this study to present a quantitative assessment of the impact of microphysical processes involving black carbon, such as emission size distributions and optical properties on aerosol cloud activation and radiative effects. Our best estimate for net direct and indirect aerosol radiative flux change between 1750 and 2000 is −0.56 W/m2. However, the direct and indirect aerosol effects are quite sensitive to the black and organic carbon size distribution and consequential mixing state. The net radiative flux change can vary between −0.32 to −0.75 W/m2 depending on these carbonaceous particle properties at emission. Taking into account internally mixed black carbon particles let us simulate correct aerosol absorption. Absorption of black carbon aerosols is amplified by sulfate and nitrate coatings and, even more strongly, by organic coatings. Black carbon mitigation scenarios generally showed reduced radiative fluxeswhen sources with a large proportion of black carbon, such as diesel, are reduced; however reducing sources with a larger organic carbon component as well, such as bio-fuels, does not necessarily lead to a reduction in positive radiative flux.

scholarly journals Quantification of aerosol chemical composition using continuous single particle measurements

2011 ◽  
Vol 11 (1) ◽  
pp. 1219-1264 ◽  
Author(s):  
C.-H. Jeong ◽  
M. L. McGuire ◽  
K. J. Godri ◽  
J. G. Slowik ◽  
P. J. G. Rehbein ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Carbon ◽  
Mass Spectrometer ◽  
Single Particle ◽  
Elemental Carbon ◽  
Rural Site ◽  
Mass Composition ◽  
Chemical Components ◽  
Particle Measurements ◽  
Mass Concentrations

Abstract. Mass concentrations of particulate matter (PM) chemical components were determined from data for 0.3 to 3.0 μm particles measured by an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) data at an urban and rural site. Hourly-averaged concentrations of nitrate, sulphate, ammonium, organic carbon, and elemental carbon, estimated based on scaled ATOFMS peak intensities of corresponding ion marker species, were compared with collocated chemical composition measurements by an Aerosol Mass Spectrometer (AMS), a Gas-Particle Ion Chromatograph (GPIC), and a Sunset Lab field OCEC analyzer. The highest correlation was found for nitrate, with correlation coefficients (Pearson r) of 0.89 and 0.85 at the urban and rural sites, respectively. ATOFMS mass calibration factors, determined for the urban site, were used to calculate mass concentrations of the major PM chemical components at the rural site. Mass reconstruction using this ATOFMS based composition data agreed very well with the total PM mass measured at the rural site. Size distributions of the ten main types of particles were resolved for the rural site and the mass composition of each particle type was determined in terms of sulphate, nitrate, ammonium, organic carbon and elemental carbon. This is the first study to estimate hourly mass concentrations of individual aerosol components and the mass composition of individual particle-types based on ATOFMS single particle measurements.

scholarly journals Intercomparison and characterization of 23 Aethalometers under laboratory and ambient air conditions: procedures and unit-to-unit variabilities

2021 ◽  
Vol 14 (4) ◽  
pp. 3195-3216
Author(s):  
Andrea Cuesta-Mosquera ◽  
Griša Močnik ◽  
Luka Drinovec ◽  
Thomas Müller ◽  
Sascha Pfeifer ◽  
...  
Keyword(s):  
Black Carbon ◽  
Ambient Air ◽  
Individual Performance ◽  
Least Square ◽  
Monitoring Networks ◽  
Average Deviation ◽  
Aerosol Sources ◽  
Maintenance Activities ◽  
The Impact ◽  
Mass Concentrations

Abstract. Aerosolized black carbon is monitored worldwide to quantify its impact on air quality and climate. Given its importance, measurements of black carbon mass concentrations must be conducted with instruments operating in quality-checked and ensured conditions to generate data which are reliable and comparable temporally and geographically. In this study, we report the results from the largest characterization and intercomparison of filter-based absorption photometers, the Aethalometer model AE33, belonging to several European monitoring networks. Under controlled laboratory conditions, a total of 23 instruments measured mass concentrations of black carbon from three well-characterized aerosol sources: synthetic soot, nigrosin particles, and ambient air from the urban background of Leipzig, Germany. The objective was to investigate the individual performance of the instruments and their comparability; we analyzed the response of the instruments to the different aerosol sources and the impact caused by the use of obsolete filter materials and the application of maintenance activities. Differences in the instrument-to-instrument variabilities from equivalent black carbon (eBC) concentrations reported at 880 nm were determined before maintenance activities (for soot measurements, average deviation from total least square regression was −2.0 % and the range −16 % to 7 %; for nigrosin measurements, average deviation was 0.4 % and the range −15 % to 17 %), and after they were carried out (for soot measurements, average deviation was −1.0 % and the range −14 % to 8 %; for nigrosin measurements, the average deviation was 0.5 % and the range −12 % to 15 %). The deviations are in most of the cases explained by the type of filter material employed by the instruments, the total particle load on the filter, and the flow calibration. The results of this intercomparison activity show that relatively small unit-to-unit variability of AE33-based particle light absorbing measurements is possible with well-maintained instruments. It is crucial to follow the guidelines for maintenance activities and the use of the proper filter tape in the AE33 to ensure high quality and comparable black carbon (BC) measurements among international observational networks.

scholarly journals Comparison of co-located refractory black carbon (rBC) and elemental carbon (EC) mass concentration measurements during field campaigns at several European sites

2021 ◽  
Vol 14 (2) ◽  
pp. 1379-1403
Author(s):  
Rosaria E. Pileci ◽  
Robin L. Modini ◽  
Michele Bertò ◽  
Jinfeng Yuan ◽  
Joel C. Corbin ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Black Carbon ◽  
Radiative Forcing ◽  
Mass Concentration ◽  
Elemental Carbon ◽  
Geometric Standard Deviation ◽  
Systematic Bias ◽  
Field Campaigns ◽  
Concentration Measurements ◽  
Mass Concentrations

Abstract. The mass concentration of black carbon (BC) particles in the atmosphere has traditionally been quantified with two methods: as elemental carbon (EC) concentrations measured by thermal–optical analysis and as equivalent black carbon (eBC) concentrations when BC mass is derived from particle light absorption coefficient measurements. Over the last decade, ambient measurements of refractory black carbon (rBC) mass concentrations based on laser-induced incandescence (LII) have become more common, mostly due to the development of the Single Particle Soot Photometer (SP2) instrument. In this work, EC and rBC mass concentration measurements from field campaigns across several background European sites (Palaiseau, Bologna, Cabauw and Melpitz) have been collated and examined to identify the similarities and differences between BC mass concentrations measured by the two techniques. All EC concentration measurements in PM2.5 were performed with the EUSAAR-2 thermal–optical protocol. All rBC concentration measurements were performed with SP2 instruments calibrated with the same calibration material as recommended in the literature. The observed values of median rBC-to-EC mass concentration ratios on the single-campaign level were 0.53, 0.65, 0.97, 1.20 and 1.29, respectively, and the geometric standard deviation (GSD) was 1.5 when considering all data points from all five campaigns. This shows that substantial systematic bias between these two quantities occurred during some campaigns, which also contributes to the large overall GSD. Despite considerable variability in BC properties and sources across the whole dataset, it was not possible to clearly assign reasons for discrepancies to one or the other method, both known to have their own specific limitations and uncertainties. However, differences in the particle size range covered by these two methods were identified as one likely reason for discrepancies. Overall, the observed correlation between rBC and EC mass reveals a linear relationship with a constant ratio, thus providing clear evidence that both methods essentially quantify the same property of atmospheric aerosols, whereas systematic differences in measured absolute values by up to a factor of 2 can occur. This finding for the level of agreement between two current state-of-the-art techniques has important implications for studies based on BC mass concentration measurements, for example for the interpretation of uncertainties in inferred BC mass absorption coefficient values, which are required for modeling the radiative forcing of BC. Homogeneity between BC mass determination techniques is also very important for moving towards a routine BC mass measurement for air quality regulations.

scholarly journals Amplification of black carbon light absorption induced by atmospheric aging: temporal variation at seasonal and diel scales in urban Guangzhou

2019 ◽  
Author(s):  
Jia Yin Sun ◽  
Cheng Wu ◽  
Dui Wu ◽  
Chunlei Cheng ◽  
Mei Li ◽  
...  
Keyword(s):  
Optical Properties ◽  
Organic Carbon ◽  
Black Carbon ◽  
Light Absorption ◽  
Dry Season ◽  
Diurnal Fluctuation ◽  
Absorption Enhancement ◽  
Wet Season ◽  
Diurnal Variability ◽  
The Impact

Abstract. Black carbon (BC) is an important climate forcer in the atmosphere. Amplification of light absorption can occur by coatings on BC aerosols, an effect that remains one of the major sources of uncertainties for accessing the radiative forcing of BC. In this study, the absorption enhancement factor (Eabs) was quantified by the minimum R squared (MRS) method using elemental carbon (EC) as the tracer. Two field campaigns were conducted in urban Guangzhou at the Jinan university super site during both wet season (July 31–September 10, 2017) and dry season (November 15, 2017–January 15, 2018) to explore the temporal dynamics of BC optical properties. The average concentration of EC was 1.94 ± 0.93 and 2.81 ± 2.01 μgC m−3 in the wet and dry seasons, respectively. Mass absorption efficiency at 520 nm by primary aerosols (MAEp520) determined by MRS exhibit a strong seasonality (8.6 m2g−1 in the wet season and 16.8 m2g−1 in the dry season). Eabs520 was higher in the wet season (1.51 ± 0.50) and lower in the dry season (1.29 ± 0.28). Absorption Ångström exponent (AAE470-660) in the dry season (1.46 ± 0.12) were higher than that in the wet season (1.37 ± 0.10). Collective evidence showed that the active biomass burning (BB) in dry season effectively altered optical properties of BC, leading to elevated MAE, MAEp and AAE in dry season comparing to those in wet season. Diurnal Eabs520 was positively correlated with AAE470-660 (R2 = 0.71) and negatively correlated with the AE33 aerosol loading compensation parameter (k) (R2 = 0.74) in the wet season, but these correlations were significantly weaker in the dry season, which may be related to the impact of BB. This result suggests that lensing effect was dominating the AAE diurnal variability during the wet season. The effect of secondary processing on Eabs diurnal dynamic were also investigated. The Eabs520 exhibit a clear dependency on secondary organic carbon to organic carbon ratio (SOC/OC). Eabs520 correlated well with nitrate, implying that gas-particle partitioning of semi-volatile compounds may potentially play an important role in steering the diurnal fluctuation of Eabs520. In dry season, the diurnal variability of Eabs520 was associated with photochemical aging as evidenced by the good correlation (R2 = 0.69) between oxidant concentrations (Ox=O3+NO2) and Eabs520.

scholarly journals Black Carbon and Elemental Carbon from Postharvest Agricultural-Waste Burning Emissions in the Indo-Gangetic Plain

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Atinderpal Singh ◽  
Prashant Rajput ◽  
Deepti Sharma ◽  
M. M. Sarin ◽  
Darshan Singh
Keyword(s):  
Black Carbon ◽  
Elemental Carbon ◽  
Agricultural Waste ◽  
Absorption Efficiency ◽  
High Mass ◽  
Gangetic Plain ◽  
Entire Study ◽  
Waste Burning ◽  
Indo Gangetic Plain ◽  
Mass Concentrations

We compare the mass concentrations of black carbon (BC) and elemental carbon (EC) from different emissions in the Indo-Gangetic Plain (IGP), using optical (Aethalometer; 880 nm) and thermooptical technique (EC-OC analyzer; 678 nm), respectively. The fractional contribution of BC mass concentration measured at two different channels (370 and 880 nm), OC/EC ratio, and non-sea-salt K+/EC ratios have been systematically monitored for representing the source characteristics of BC and EC in this study. The mass concentrations of BC varied from 8.5 to 19.6, 2.4 to 18.2, and 2.2 to 9.4 μg m−3during October-November (paddy-residue burning emission), December–March (emission from bio- and fossil-fuel combustion) and April-May (wheat-residue burning emission), respectively. In contrast, the mass concentrations of EC varied from 3.8 to 17.5, 2.3 to 8.9, and 2.0 to 8.8 μg m−3during these emissions, respectively. The BC/EC ratios conspicuously greater than 1.0 have been observed during paddy-residue burning emissions associated with high mass concentrations of EC, OC, and OC/EC ratio. The Ångström exponent (α) derived from Aethalometer data is approximately 1.5 for the postharvest agricultural-waste burning emissions, hitherto unknown for the IGP. The mass absorption efficiency (MAE) of BC and EC centers at ~1–4 m2 g−1and 2-3 m2 g−1during the entire study period in the IGP.

scholarly journals Bacterial-viral interactions in the sea surface microlayer of a black carbon-dominated tropical coastal ecosystem (Halong Bay, Vietnam)

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
A.S. Pradeep Ram ◽  
X. Mari ◽  
J. Brune ◽  
J.P. Torréton ◽  
V.T. Chu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Bacterial Production ◽  
Lytic Infection ◽  
Sea Surface ◽  
Surface Microlayer ◽  
Sea Surface Microlayer ◽  
Halong Bay ◽  
Virus Interactions ◽  
The Impact

Increasing human activity has raised concerns about the impact of deposition of anthropogenic combustion aerosols (i.e., black carbon; BC) on marine processes. The sea surface microlayer (SML) is a key gate for the introduction of atmospheric BC into the ocean; however, relatively little is known of the effects of BC on bacteria-virus interactions, which can strongly influence microbially mediated processes. To study the impact of BC on bacteria-virus interactions, field investigations involving collection from the SML and underlying water were carried out in Halong Bay (Vietnam). Most inorganic nutrient concentrations, as well as dissolved organic carbon, were modestly but significantly higher (p = 0.02–0.05) in the SML than in underlying water. The concentrations of particulate organic carbon (though not chlorophyll a) and of total particulate carbon, which was composed largely of particulate BC (mean = 1.7 ± 6.4 mmol L–1), were highly enriched in the SML, and showed high variability among stations. On average, microbial abundances (both bacteria and viruses) and bacterial production were 2- and 5fold higher, respectively, in the SML than in underlying water. Significantly lower bacterial production (p < 0.01) was observed in the particulate fraction (>3 µm) compared to the bulk sample, but our data overall suggest that bacterial production in the SML was stimulated by particulate BC. Higher bacterial production in the SML than in underlying water supported high viral lytic infection rates (from 5.3 to 30.1%) which predominated over percent lysogeny (from undetected to 1.4%). The sorption of dissolved organic carbon by black carbon, accompanied by the high lytic infection rate in the black carbon-enriched SML, may modify microbially mediated processes and shift the net ecosystem metabolism (ratio of production and respiration) to net heterotrophy and CO2 production in this critical layer between ocean and atmosphere.

scholarly journals Aerosol particle measurements at three stationary sites in the megacity of Paris during summer 2009: meteorology and air mass origin dominate aerosol particle composition and size distribution

2013 ◽  
Vol 13 (2) ◽  
pp. 933-959 ◽  
Author(s):  
F. Freutel ◽  
J. Schneider ◽  
F. Drewnick ◽  
S.-L. von der Weiden-Reinmüller ◽  
M. Crippa ◽  
...  
Keyword(s):  
Particle Size ◽  
Black Carbon ◽  
Aerosol Particle ◽  
Organic Aerosol ◽  
Air Mass ◽  
Air Masses ◽  
Aerosol Mass ◽  
The Impact ◽  
Air Mass Origin ◽  
Mass Concentrations

Abstract. During July 2009, a one-month measurement campaign was performed in the megacity of Paris. Amongst other measurement platforms, three stationary sites distributed over an area of 40 km in diameter in the greater Paris region enabled a detailed characterization of the aerosol particle and gas phase. Simulation results from the FLEXPART dispersion model were used to distinguish between different types of air masses sampled. It was found that the origin of air masses had a large influence on measured mass concentrations of the secondary species particulate sulphate, nitrate, ammonium, and oxygenated organic aerosol measured with the Aerodyne aerosol mass spectrometer in the submicron particle size range: particularly high concentrations of these species (about 4 μg m−3, 2 μg m−3, 2 μg m−3, and 7 μg m−3, respectively) were measured when aged material was advected from continental Europe, while for air masses originating from the Atlantic, much lower mass concentrations of these species were observed (about 1 μg m−3, 0.2 μg m−3, 0.4 μg m−3, and 1–3 μg m−3, respectively). For the primary emission tracers hydrocarbon-like organic aerosol, black carbon, and NOx it was found that apart from diurnal source strength variations and proximity to emission sources, local meteorology had the largest influence on measured concentrations, with higher wind speeds leading to larger dilution and therefore smaller measured concentrations. Also the shape of particle size distributions was affected by wind speed and air mass origin. Quasi-Lagrangian measurements performed under connected flow conditions between the three stationary sites were used to estimate the influence of the Paris emission plume onto its surroundings, which was found to be rather small. Rough estimates for the impact of the Paris emission plume on the suburban areas can be inferred from these measurements: Volume mixing ratios of 1–14 ppb of NOx, and upper limits for mass concentrations of about 1.5 μg m−3 of black carbon and of about 3 μg m−3 of hydrocarbon-like organic aerosol can be deduced which originate from both, local emissions and the overall Paris emission plume. The secondary aerosol particle phase species were found to be not significantly influenced by the Paris megacity, indicating their regional origin. The submicron aerosol mass concentrations of particulate sulphate, nitrate, and ammonium measured during time periods when air masses were advected from eastern central Europe were found to be similar to what has been found from other measurement campaigns in Paris and south-central France for this type of air mass origin, indicating that the results presented here are also more generally valid.

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