Fireworks—a source of nanoparticles, PM2.5, PM10, and carbonaceous aerosols

AbstractFireworks pollute the local atmosphere with various air pollutants, which can pose a health hazard for the local population. Mass and number concentrations of aerosols were measured before, during, and after the 2016/2017 New Year event in Ljubljana, Slovenia. Our findings highlight the negative impact of fireworks on the environment. First, both the mass concentration of black carbon and the number of concentrations of nanoparticles between 80 and 150 nm increased shortly after midnight. Second, on Jan 1, 2017, there was an increase in the average daily mass concentrations of PM10 and PM2.5. Third, on this day, our devices also detected increased air pollution by Al, Ba, Sr, and Cu, that is, heavy metals usually associated with fireworks. Their Jan 1 mass concentrations were more than 10 times (and Sr more than 140 times) higher than their average daily mass concentrations from Jan 3 (when their mass concentrations returned to more normal levels) to Jan 31. We also found that pairwise correlations between nanoparticles, PM10, and black carbon are positive, strong, and statistically significant. Besides carbon, the chemical analysis of the collected particles revealed the presence of typical elements used in pyrotechnic devices and their significant positive correlation.

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Black carbon variability since preindustrial times in Eastern part of Europe reconstructed from Mt Elbrus, Caucasus ice cores

10.5194/acp-2016-804 ◽

2016 ◽

Author(s):

Saehee Lim ◽

Xavier Faïn ◽

Patrick Ginot ◽

Vladimir Mikhalenko ◽

Stanislav Kutuzov ◽

...

Keyword(s):

Black Carbon ◽

20Th Century ◽

Biomass Burning ◽

Mass Concentration ◽

Ice Core ◽

Ice Cores ◽

Anthropogenic Emissions ◽

Ice Core Record ◽

Summer Time ◽

Mass Concentrations

Abstract. Black carbon (BC), emitted by fossil fuel combustion and biomass burning, is the second largest man-made contributor to global warming after carbon dioxide (Bond et al., 2013). However, limited information exists on its past emissions and atmospheric variability. In this study, we present the first high-resolution record of refractory BC (rBC, including mass concentration and size) reconstructed from ice cores drilled at a high-altitude Eastern European site in Mt. Elbrus (ELB), Caucasus (5115 m a.s.l.). The ELB ice core record, covering the period 1825–2013, reflects the atmospheric load of rBC particles at the ELB site transported from the European continent with a larger rBC input from sources located in the Eastern part of Europe. In the first half of the 20th century, European anthropogenic emissions resulted in a 1.5-fold increase in the ice core rBC mass concentrations as respect to its level in the preindustrial era (before 1850). The rBC mass concentrations increased by a 5-fold in 1960–1980, followed by a decrease until ~ 2000. Over the last decade, the rBC signal for summer time slightly increased. We have compared the signal with the atmospheric BC load simulated using past BC emissions (ACCMIP and MACCity inventories) and taken into account the contribution of different geographical region to rBC distribution and deposition at the ELB site. Interestingly, the observed rBC variability in the ELB ice core record since the 1960s is not in perfect agreement with the simulated atmospheric BC load. Similar features between the ice core rBC record and the best scenarios for the atmospheric BC load support that anthropogenic BC increase in the 20th century is reflected in the ELB ice core record. However, the peak in BC mass concentration observed in ~ 1970 in the ice core is estimated to occur a decade later from past inventories. BC emission inventories for the period 1960s–1970s may be underestimating European anthropogenic emissions. Furthermore, for summer time snow layers of the last 2000s, the slightly increasing trend of rBC deposition likely reflects recent changes in anthropogenic and biomass burning BC emissions in the Eastern part of Europe. Our study highlights that the past changes in BC emissions of Eastern Europe need to be considered in assessing on-going air quality regulation.

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Spatial, temporal and source contribution assessments of BC over the northern interior of South Africa

10.5194/acp-2016-934 ◽

2016 ◽

Author(s):

Kgaugelo Euphinia Chiloane ◽

Johan Paul Beukes ◽

Pieter Gideon van Zyl ◽

Petra Maritz ◽

Ville Vakkari ◽

...

Keyword(s):

South Africa ◽

Black Carbon ◽

Southern Africa ◽

Mass Concentration ◽

Source Region ◽

Measurement Data ◽

Concentration Data ◽

Power Stations ◽

Concentration Levels ◽

Mass Concentrations

Abstract. After carbon dioxide (CO2), aerosol black carbon (BC) is considered to be the second most important contributor to global warming. Africa is one of the least studied continents, although it is regarded as the largest source region of atmospheric BC. Southern Africa is an important sub-source region, with savannah and grassland fires likely to contribute to elevated BC mass concentration levels. South Africa is the economic and industrial hub of southern Africa. To date, little BC mass concentration data have been presented for South Africa in the peer-reviewed public domain. This paper presents equivalent black carbon (eBC) (derived from an optical absorption method) data collected from three sites, where continuous measurements have been conducted, i.e. Elandsfontein (EL), Welgegund (WG) and Marikana (MA), as well elemental carbon (EC) (determined by evolved carbon method) at five sites where samples were collected once a month on a filter and analysed off-line, i.e. Louis Trichardt (LT), Skukuza (SK), Vaal Triangle (VT), Amersfoort (AM) and Botsalano (BS). All these sites are located in the interior of South Africa. Analyses of eBC and EC spatial mass concentration patterns across the eight sites indicate that the mass concentrations in the South African interior are in general higher than what has been reported for the developed world and that different sources are likely to influence different sites. The mean eBC or EC mass concentrations for the background sites (WG, LT, SK, BS) and sites influenced by industrial activities and/or nearby settlements (EL, MA, VT and AM) ranged between 0.7 and 1.1, and 1.3 and 1.4 µg/m3, respectively. Similar seasonal patterns were observed at all three sites where continuous measurement data were collected (EL, MA and WG), with the highest eBC mass concentrations measured during June to October, indicating contributions from household combustion in the cold winter months (June–August), as well as savannah and grassland fires during the dry season (May to mid-October). Diurnal patterns of eBC at EL, MA and WG indicated maximum concentrations in the early mornings and late evenings, and minima during daytime. From the patterns it could be deduced that for MA and WG, household combustion and savannah, and grassland fires were the most significant sources, respectively. Possible contributing sources were explored in greater detail for EL, with five main sources being identified as coal-fired power stations, pyrometallurgical smelters, traffic, household combustion, as well as savannah and grassland fires. Industries on the Mpumalanga Highveld are often blamed for all forms of pollution, due to the NO2 hotspot over this area that is attributed to NOx emissions from industries and vehicle emissions from the Johannesburg-Pretoria megacity. However, a comparison of source strengths indicated that household combustion, and savannah and grassland fires were the most significant sources of eBC, particularly during winter and spring months, while coal-fired power stations, pyro-metallurgical smelters and traffic contribute to eBC mass concentration levels year round.

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Vertical and horizontal distribution of sub-micron aerosol chemical composition and physical characteristics across Northern India, during the pre-monsoon and monsoon seasons

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acp-2018-1109 ◽

2018 ◽

pp. 1-31

Author(s):

James Brooks ◽

James D. Allan ◽

Paul I. Williams ◽

Dantong Liu ◽

Cathryn Fox ◽

...

Keyword(s):

Black Carbon ◽

Total Mass ◽

Mass Concentration ◽

Monsoon Season ◽

Aerosol Layer ◽

Gangetic Plain ◽

Submicron Aerosol ◽

Aerosol Mass ◽

Indo Gangetic Plain ◽

Mass Concentrations

Abstract. The vertical distribution in the physical and chemical properties of submicron aerosol has been characterised across northern India for the first time using airborne in-situ measurements. This study focusses primarily on the Indo-Gangetic Plain, a low-lying area in the north of India which commonly experiences high aerosol mass concentrations prior to the monsoon season. Data presented are from the UK Facility for Airborne Atmospheric Measurements BAe-146 research aircraft that performed flights in the region during the 2016 pre-monsoon (11th and 12th June) and monsoon (30th June to 11th July) seasons. Inside the Indo-Gangetic Plain boundary layer, organic matter dominated the submicron aerosol mass (43&thinsp;%) followed by sulphate (29&thinsp;%), ammonium (14&thinsp;%), nitrate (7&thinsp;%) and black carbon (7&thinsp;%). However, outside the Indo-Gangetic Plain, sulphate was the dominant species contributing 44&thinsp;% to the total submicron aerosol mass in the boundary layer, followed by organic matter (30&thinsp;%), ammonium (14&thinsp;%), nitrate (6&thinsp;%) and black carbon (6&thinsp;%). Chlorine mass concentrations were negligible throughout the campaign. Black carbon mass concentrations were higher inside the Indo-Gangetic Plain (2&thinsp;µg/m3 std) compared to outside (1&thinsp;µg/m3 std). Nitrate appeared to be controlled by thermodynamic processes, with increased mass concentration in conditions of lower temperature and higher relative humidity. Increased mass and number concentrations were observed inside the Indo-Gangetic Plain and the aerosol was more absorbing in this region, whereas outside the Indo-Gangetic Plain the aerosol was larger in size and more scattering in nature, suggesting greater dust presence especially in northwest India. The aerosol composition remained largely similar as the monsoon season progressed, but the total aerosol mass concentrations decreased by ~&thinsp;50&thinsp;% as the rainfall arrived; the pre-monsoon average total mass concentration was 30&thinsp;µg/m3 std compared to a monsoon average total mass concentration of 10&ndash;20&thinsp;µg/m3 std. However, this mass concentration decrease was less noteworthy (~&thinsp;20&ndash;30&thinsp;%) over the Indo-Gangetic Plain, likely due to the strength of emission sources in this region. Decreases occurred in coarse mode aerosol, with the fine mode fraction increasing with monsoon arrival. In the aerosol vertical profile, inside the Indo-Gangetic Plain during the pre-monsoon, organic aerosol and absorbing aerosol species dominated in the lower atmosphere (<&thinsp;1.5&thinsp;km) with sulphate, dust and other scattering aerosol species enhanced in an elevated aerosol layer above 1.5&thinsp;km with maximum aerosol height ~&thinsp;6&thinsp;km. As the monsoon progressed into this region, the elevated aerosol layer diminished, the aerosol maximum height reduced to ~&thinsp;2&thinsp;km and the total mass concentrations decreased by ~&thinsp;50&thinsp;%. The dust and sulphate-dominated aerosol layer aloft was removed upon monsoon arrival, highlighted by an increase in fine mode fraction throughout the profile.

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

Atmospheric Measurement Techniques ◽

10.5194/amt-14-1379-2021 ◽

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.

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Analysis of the Characteristics and Sources of Carbonaceous Aerosols in PM2.5 in the Beijing, Tianjin, and Langfang Region, China

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15071483 ◽

2018 ◽

Vol 15 (7) ◽

pp. 1483 ◽

Cited By ~ 11

Author(s):

Mengxi Qi ◽

Lei Jiang ◽

Yixuan Liu ◽

Qiulin Xiong ◽

Chunyuan Sun ◽

...

Keyword(s):

Organic Carbon ◽

Mass Concentration ◽

Road Dust ◽

Total Carbon ◽

Ratio Method ◽

Carbonaceous Aerosols ◽

Average Mass ◽

Sources Of Pollution ◽

Main Component ◽

Mass Concentrations

PM2.5 samples from Beijing, Tianjin, and Langfang were simultaneously collected from 20 November 2016 to 25 December 2016, and the organic carbon (OC) and elemental carbon (EC) content in the samples were measured and analyzed. The pollution characteristics and sources of OC and EC in atmospheric PM2.5 for three adjacent cities were discussed. The average mass concentrations of OC in PM2.5 in Beijing, Tianjin, and Langfang were 27.93 ± 23.35 μg/m3, 25.27 ± 12.43 μg/m3, and 52.75 ± 37.97 μg/m3, respectively, and the mean mass concentrations of EC were 6.61 ± 5.13 μg/m3, 6.14 ± 2.84 μg/m3, and 12.06 ± 6.81 μg/m3, respectively. The average mass concentration of total carbon (TC) accounted for 30.5%, 24.8%, and 49% of the average mass concentration of PM2.5 in the atmosphere. The total carbonaceous matter (TCA) in Beijing, Tianjin, and Langfang was 51.29, 46.57, and 96.45 μg/m3, respectively. The TCA was the main component of PM2.5 in the region. The correlation between OC and EC in the three cities showed R2 values of 0.882, 0.633, and 0.784 for Beijing, Tianjin, and Langfang, respectively, indicating that the sources of urban carbonaceous aerosols had good consistency and stability. The OC/EC values of the three sampling points were 4.48 ± 1.45, 4.42 ± 1.77, and 4.22 ± 1.29, respectively, considerably greater than 2, indicating that the main sources of pollution were automobile exhaust, and the combustion of coal and biomass. The OC/EC minimum ratio method was used to estimate the secondary organic carbon (SOC) content in Beijing, Tianjin and Langfang. Their values were 10.73, 10.71, and 19.51, respectively, which accounted for 38%, 42%, and 37% of the average OC concentration in each city, respectively. The analysis of the eight carbon components showed that the main sources of pollutants in Beijing, Tianjin, and Langfang were exhaust emissions from gasoline vehicles, but the combustion of coal and biomass was relatively low. The pollution of road dust was more serious in Tianjin than in Beijing and Langfang. The contribution of biomass burning and coal-burning pollution sources to atmospheric carbon aerosols in Langfang was more prominent than that of Beijing and Tianjin.

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Representativeness and variability of PM2.5 mass concentrations and black carbon near traffic and urban background monitoring stations/Repräsentativität und Variabilität von PM2.5-Massenkonzentrationen und schwarzem Kohlenstoff in der Nähe von Verkehrs- und städtischen Luftgütemessstationen.

Gefahrstoffe ◽

10.37544/0949-8036-2019-06-31 ◽

2019 ◽

Vol 79 (06) ◽

pp. 217-226

Author(s):

H. D. Alas ◽

S. Pfeifer ◽

A. Wiesner ◽

B. Wehner ◽

K. Weinhold ◽

...

Keyword(s):

Air Pollution ◽

Black Carbon ◽

Urban Areas ◽

Mass Concentration ◽

Spatial Distributions ◽

Urban Background ◽

Regular Monitoring ◽

The City ◽

Mass Concentrations ◽

Monitoring Stations

Mobile measurements of PM2.5 and black carbon (BC) mass concentrations were performed near regular monitoring stations in order to gain deeper understanding of the drivers of pedestrian exposure to traffic-related air pollution. The following investigations have been done: A) Yearlong measurements in an area around a street canyon approximately 3 km airline distance from the city center of Leipzig showed that the spatial distributions of both pollutants are elevated during wintertime. The patterns of the BC mass concentration, however, consistently showed a strong influence from traffic emissions in the street, while the PM2.5 mass concentration was more dependent on the regional background and less on urban sources. B) Measurements in the city of Dresden near two regular monitoring stations, one at a roadside and one in urban background areas revealed differences between the two in terms of the BC mass concentrations, with slightly higher concentrations at the traffic area. However, no significant differences between the spatial distributions of PM2.5 mass concentrations were observed. The background measurements of the PM2.5 mass concentrations seem to be generally representative for the residential area. C) Measurements near a regular monitoring station located at a junction of the inner-city ring road of Leipzig showed that it is representative of its immediate vicinity in terms of BC mass concentrations. However, the PM2.5 mass concentration varied by a factor 2, reaching the highest levels near in the central tram station about 200 m away. The central tram station seems to significantly influence the PM2.5 mass concentration. These results of the three studies provide a better understanding of the variability of these two parameters in urban areas in Leipzig and Dresden, helping local policy makers to interpret better the measured air pollution.

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Decreasing Trends of Particle Number and Black Carbon Mass Concentrations at 16 Observational Sites in Germany from 2009 to 2018

10.5194/acp-2019-754 ◽

2019 ◽

Author(s):

Jia Sun ◽

Wolfram Birmili ◽

Markus Hermann ◽

Thomas Tuch ◽

Kay Weinhold ◽

...

Keyword(s):

Time Series ◽

Black Carbon ◽

Urban Areas ◽

Mass Concentration ◽

Particle Number ◽

Regional Scale ◽

Particle Diameter ◽

Anthropogenic Emissions ◽

Mitigation Policies ◽

Mass Concentrations

Abstract. Anthropogenic emissions are a dominant contributor to air pollution. Consequently, mitigation policies have attempted to reduce anthropogenic pollution emissions in Europe since the 1990s. To evaluate the effectiveness of these mitigation policies, the German Ultrafine Aerosol Network (GUAN) was established in 2008, focusing on black carbon and sub-micrometer aerosol particles, especially ultrafine particles. In this investigation, trends of the size-resolved particle number concentrations (PNC) and the equivalent black carbon (eBC) mass concentration over a 10-year period (2009–2018) were evaluated for 16 observational sites for different environments among GUAN. The trend analysis was done for both, the full-length time series and on subsets of the time series in order to test the reliability of the results. The results show generally decreasing trends of both, the PNCs for all size ranges as well as eBC mass concentrations in all environments, except PNC in 10–30 nm at regional background and mountain sites. The annual slope of the eBC mass concentration varies between −7.7 % and −1.8 % per year. The slopes of the PNCs varies from −6.3 % to 2.7 %, −7.0 % to −2.0 %, and −9.5 % to −1.5 % per year (only significant trends) for 10–30 nm, 30–200 nm, and 200–800 nm particle diameter, respectively. The regional Mann-Kendall test yielded regional-scale trends of eBC mass concentration, N[30–200] and N[200–800] of −3.8 %, −2.0 % and −2.4 %, respectively, indicating an overall decreasing trend for eBC mass concentration and sub-micrometer PNC (except N[10–30]) all over Germany. The most significant decrease was observed on working days and during daytime in urban areas, which implies a strong evidence of reduced anthropogenic emissions. For the seasonal trends, stronger reductions were observed in winter. Possible reasons for this reduction can be the increased average ambient temperatures and wind speed in winter, which resulted in less domestic heating and stronger dilution. In addition, decreased precipitation in summer also diminishes the decrease of the PNCs and eBC mass concentration. For the period of interest, there were no significant changes in long-range transport patterns. The most likely factors for the observed decreasing trends are declining anthropogenic emissions due to emission mitigation policies of the European Union.

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Comparison of co–located rBC and EC mass concentration measurements during field campaigns at several European sites

10.5194/amt-2020-192 ◽

2020 ◽

Author(s):

Rosaria E. Pileci ◽

Robin L. Modini ◽

Michele Bertò ◽

Jinfeng Yuan ◽

Joel C. Corbin ◽

...

Keyword(s):

Absorption Coefficient ◽

Black Carbon ◽

Mass Concentration ◽

Geometric Standard Deviation ◽

Systematic Bias ◽

Good Precision ◽

Field Campaigns ◽

Concentration Measurements ◽

Mass Concentrations ◽

Concentration Ratios

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 (Paris, 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 SP2s calibrated with the same calibration material as recommended in the literature. The median ratio between observed rBC and EC mass concentrations was 0.92, when considering all data points from all five campaigns, and the corresponding geometric standard deviation (GSD) was 1.5. The minimal and maximal observed values of median rBC to EC mass concentration ratios on single campaign level were 0.53 and 1.29, respectively. This shows that substantial systematic bias between these two quantities occurred during some campaigns, which also contributes to the large overall GSD. On single campaign level, the relative spread of individual rBC to EC mass concentration ratios was typically between a factor of 1.2 and 1.3 (1 GSD), which indicates fairly good precision of both methods. Despite considerable variability of BC properties and sources across the whole data set, 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. In particular, rBC to EC mass concentration ratios were found to be systematically less than unity, despite applying a correction for small BC cores that remain undetected by the SP2. This was observed when the rBC mass size distribution was shifted towards smaller modal diameter, which occurred during traffic emission dominated episodes. Overall, the high correlation between rBC and EC mass concentrations indicates 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 of inferred BC mass absorption coefficient values, which are required for modelling the radiative forcing of BC. Homogeneity between BC mass determination techniques is very important also towards a routine BC mass measurement for air quality or human health regulations.

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Vertical and horizontal distribution of submicron aerosol chemical composition and physical characteristics across northern India during pre-monsoon and monsoon seasons

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-5615-2019 ◽

2019 ◽

Vol 19 (8) ◽

pp. 5615-5634 ◽

Cited By ~ 19

Author(s):

James Brooks ◽

James D. Allan ◽

Paul I. Williams ◽

Dantong Liu ◽

Cathryn Fox ◽

...

Keyword(s):

Black Carbon ◽

Mass Concentration ◽

Monsoon Season ◽

Western India ◽

Aerosol Layer ◽

Gangetic Plain ◽

Submicron Aerosol ◽

Aerosol Mass ◽

Indo Gangetic Plain ◽

Mass Concentrations

Abstract. The vertical distribution in the physical and chemical properties of submicron aerosol has been characterised across northern India for the first time using airborne in situ measurements. This study focusses primarily on the Indo-Gangetic Plain, a low-lying area in the north of India which commonly experiences high aerosol mass concentrations prior to the monsoon season. Data presented are from the UK Facility for Airborne Atmospheric Measurements BAe-146 research aircraft that performed flights in the region during the 2016 pre-monsoon (11 and 12 June) and monsoon (30 June to 11 July) seasons. Inside the Indo-Gangetic Plain boundary layer, organic matter dominated the submicron aerosol mass (43&thinsp;%) followed by sulfate (29&thinsp;%), ammonium (14&thinsp;%), nitrate (7&thinsp;%) and black carbon (7&thinsp;%). However, outside the Indo-Gangetic Plain, sulfate was the dominant species, contributing 44&thinsp;% to the total submicron aerosol mass in the boundary layer, followed by organic matter (30&thinsp;%), ammonium (14&thinsp;%), nitrate (6&thinsp;%) and black carbon (6&thinsp;%). Chlorine mass concentrations were negligible throughout the campaign. Black carbon mass concentrations were higher inside the Indo-Gangetic Plain (2&thinsp;µg&thinsp;m−3) compared to outside (1&thinsp;µg&thinsp;m−3). Nitrate appeared to be controlled by thermodynamic processes, with increased mass concentration in conditions of lower temperature and higher relative humidity. Increased mass and number concentrations were observed inside the Indo-Gangetic Plain and the aerosol was more absorbing in this region, whereas outside the Indo-Gangetic Plain the aerosol was larger in size and more scattered in nature, suggesting greater dust presence, especially in north-western India. The aerosol composition remained largely similar as the monsoon season progressed, but the total aerosol mass concentrations decreased by ∼50&thinsp;% as the rainfall arrived; the pre-monsoon average total mass concentration was 30&thinsp;µg&thinsp;m−3 compared to a monsoon average total mass concentration of 10–20&thinsp;µg&thinsp;m−3. However, this mass concentration decrease was less noteworthy (∼20&thinsp;%–30&thinsp;%) over the Indo-Gangetic Plain, likely due to the strength of emission sources in this region. Decreases occurred in coarse mode aerosol, with the fine mode fraction increasing with monsoon arrival. In the aerosol vertical profile, inside the Indo-Gangetic Plain during the pre-monsoon, organic aerosol and absorbing aerosol species dominated in the lower atmosphere (&lt;1.5&thinsp;km), with sulfate, dust and other scattering aerosol species enhanced in an elevated aerosol layer above 1.5&thinsp;km with maximum aerosol height ∼6&thinsp;km. The elevated concentration of dust at altitudes &gt;1.5&thinsp;km is a clear indication of dust transport from the Great Indian Desert, also called the Thar Desert, in north-western India. As the monsoon progressed into this region, the elevated aerosol layer diminished, the aerosol maximum height reduced to ∼2&thinsp;km. The dust and sulfate-dominated aerosol layer aloft was removed upon monsoon arrival, highlighted by an increase in fine mode fraction throughout the profile.

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Black carbon variability since preindustrial times in the eastern part of Europe reconstructed from Mt. Elbrus, Caucasus, ice cores

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-3489-2017 ◽

2017 ◽

Vol 17 (5) ◽

pp. 3489-3505 ◽

Cited By ~ 17

Author(s):

Saehee Lim ◽

Xavier Faïn ◽

Patrick Ginot ◽

Vladimir Mikhalenko ◽

Stanislav Kutuzov ◽

...

Keyword(s):

Black Carbon ◽

20Th Century ◽

Biomass Burning ◽

Mass Concentration ◽

Ice Core ◽

Ice Cores ◽

Anthropogenic Emissions ◽

Geographical Regions ◽

Ice Core Record ◽

Mass Concentrations

Abstract. Black carbon (BC), emitted by fossil fuel combustion and biomass burning, is the second largest man-made contributor to global warming after carbon dioxide (Bond et al., 2013). However, limited information exists on its past emissions and atmospheric variability. In this study, we present the first high-resolution record of refractory BC (rBC, including mass concentration and size) reconstructed from ice cores drilled at a high-altitude eastern European site in Mt. Elbrus (ELB), Caucasus (5115 m a.s.l.). The ELB ice core record, covering the period 1825–2013, reflects the atmospheric load of rBC particles at the ELB site transported from the European continent with a larger rBC input from sources located in the eastern part of Europe. In the first half of the 20th century, European anthropogenic emissions resulted in a 1.5-fold increase in the ice core rBC mass concentrations with respect to its level in the preindustrial era (before 1850). The summer (winter) rBC mass concentrations increased 5-fold (3.3-fold) in 1960–1980, followed by a decrease until ∼  2000. Over the last decade, the rBC signal for summertime slightly increased. We have compared the signal with the atmospheric BC load simulated using past BC emissions (ACCMIP and MACCity inventories) and taken into account the contribution of different geographical regions to rBC distribution and deposition at the ELB site. Interestingly, the observed rBC variability in the ELB ice core record since the 1960s is not in perfect agreement with the simulated atmospheric BC load. Similar features between the ice core rBC record and the best scenarios for the atmospheric BC load support anthropogenic BC increase in the 20th century being reflected in the ELB ice core record. However, the peak in BC mass concentration observed in ∼  1970 in the ice core is estimated to occur a decade later from past inventories. BC emission inventories for the period 1960s–1970s may be underestimating European anthropogenic emissions. Furthermore, for summertime snow layers of the 2000s, the slightly increasing trend of rBC deposition likely reflects recent changes in anthropogenic and biomass burning BC emissions in the eastern part of Europe. Our study highlights that the past changes in BC emissions of eastern Europe need to be considered in assessing ongoing air quality regulation.

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