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Cao N, Chen L, Liu Y, Wang J, Yang S, Su D, Mi K, Gao S, Zhang H. Spatiotemporal distribution, light absorption characteristics, and source apportionments of black and brown carbon in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170796. [PMID: 38336053 DOI: 10.1016/j.scitotenv.2024.170796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/30/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
Black carbon (BC) and brown carbon (BrC) are aerosols that absorb light and thereby contribute to climate change. In this study, the light absorption properties and spatiotemporal distributions of equivalent BC (eBC) and BrC aerosols were determined based on continuous measurements of aerosol light absorption from January to August 2017, using a seven-channel aethalometer at 49 sampling sites in China. The source apportionments of BC and BrC were identified using the BC/PM2.5, absorption Ångström exponent, the concentration-weighted trajectory method, and the random forest model. Based on the results, BC was the dominant light absorber, whereas BrC was responsible for a higher proportion of the light absorption in northern compared to southern China. The light absorption of BrC was highest in winter (34.3 Mm-1), followed by spring (19.0 Mm-1) and summer (3.6 Mm-1). The combustion of liquid fuels accounted for over 50 % of the light absorption coefficient of BC in most cities and the importance of carbon monoxide (CO) and nitrogen dioxide (NO2) was over 10 % for BC emitted by liquid fuel combustion, based on the random forest model. The contribution of solid fuel combustion to BC in the north was larger than that in the southern regions as coal combustion and crop residue burning are important emission sources of BC in most northern cities. The contribution of primary BrC to light absorption was high in some northern cities, whereas that of secondary BrC was prevalent in some southern cities. The diurnal variations in secondary BrC were affected by changes in odd oxygen and relative humidity, which promoted the photobleaching of the chromophores and aqueous-phase reactions of secondary BrC.
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Affiliation(s)
- Nan Cao
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Li Chen
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China.
| | - Yusi Liu
- State Key Laboratory of Severe Weather, Key Laboratory for Atmospheric Chemistry of China Meteorology Administration, Chinese Academy of Meteorological Sciences, Beijing 100081, China.
| | - Jing Wang
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Shuangqin Yang
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Die Su
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Ke Mi
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Shuang Gao
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Hu Zhang
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
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2
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Ferrero L, Losi N, Rigler M, Gregorič A, Colombi C, D'Angelo L, Cuccia E, Cefalì AM, Gini I, Doldi A, Cerri S, Maroni P, Cipriano D, Markuszewski P, Bolzacchini E. Determining the Aethalometer multiple scattering enhancement factor C from the filter loading parameter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170221. [PMID: 38280585 DOI: 10.1016/j.scitotenv.2024.170221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/27/2023] [Accepted: 01/14/2024] [Indexed: 01/29/2024]
Abstract
Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world. By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter CAE) on an yearly and a monthly basis. The method was developed in Milan, where Aethalometer measurements were compared with MAAP data; the comparison showed a good agreement in terms of equivalent black carbon (R2 = 0.93; slope = 1.02 and a negligible intercept = 0.12 μg m-3) leading to a yearly experimental multiple scattering enhancement factor of 2.51 ± 0.04 (hereinafter CMAAP). On a yearly time base the CAE values obtained using the new approach was 2.52 ± 0.01, corresponding to the experimental one (CMAAP). Considering the seasonal behavior, higher experimental CMAAP and computed CAE values were found in summer (2.83 ± 0.12) whereas, the lower ones in winter/early-spring (2.37 ± 0.03), in agreement with the single scattering albedo behavior in the Po Valley. Overall, the agreement between the experimental CMAAP and CAE showed a root mean squared error (RMSE) of just 0.038 on the CMAAP prediction, characterized by a slope close to 1 (1.001 ± 0.178), a negligible intercept (-0.002 ± 0.455) and a high degree of correlation (R2 = 0.955). From an environmental point of view, the application of a dynamic (space/time) determination of CAE increases the accuracy of the aerosol heating rate (compared to applying a fixed C value) up to 16 % solely in Milan, and to 114 % when applied in the Arctic at 80°N.
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Affiliation(s)
- L Ferrero
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy.
| | - N Losi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - M Rigler
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - A Gregorič
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia; Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia
| | - C Colombi
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy
| | - L D'Angelo
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy; Institute for Atmospheric and Environmental Sciences, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany
| | - E Cuccia
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy
| | - A M Cefalì
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy; RSE - Ricerca sul Sistema Energetico S.p.A., via Rubattino 54, 20134 Milano, Italy
| | - I Gini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - A Doldi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - S Cerri
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - P Maroni
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - D Cipriano
- RSE - Ricerca sul Sistema Energetico S.p.A., via Rubattino 54, 20134 Milano, Italy
| | - P Markuszewski
- Institute of Oceanology, Polish Academy of Sciences, 81-712 Sopot, Poland; Bolin Centre for Climate Research and Department of Environmental Science, Stockholm University, 10691 Stockholm, Sweden
| | - E Bolzacchini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
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3
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Gao P, Deng R, Jia S, Li Y, Wang X, Xing Q. Effects of combustion temperature on the optical properties of brown carbon from biomass burning. J Environ Sci (China) 2024; 137:302-309. [PMID: 37980017 DOI: 10.1016/j.jes.2022.12.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/27/2022] [Accepted: 12/21/2022] [Indexed: 11/20/2023]
Abstract
Biomass burning has been known as one of main sources of Brown Carbon (BrC) in atmosphere. In this study, by controlling the combustion temperature at 250°C, 350°C, and 450°C, the methanol soluble organic carbon (MSOC) and methanol insoluble carbon (MISC) from pine wood burning was collected by impinger. UV-Vis, excitation emission matrix (EEM), TEM and FTIR spectra were applied to investigate the properties of BrC collected. For MSOC at 250°C and 350°C, all the spectral profiles of UV-Vis absorption and excitation emission matrix are almost the same, while the EEM of MSOC at 450°C are different from that of the other two. For MISC fluorescence was observed only in the case of 450°C. In the FTIR spectra, with the temperature increasing the peaks associated to the oxygen-contained functions was weakened, indicating the formation of the fluorophores with larger conjugated system, especially aromatic hydrocarbons. Our results show that biomass combustion at low temperature produces more oxygen-riched BrC, which possesses relatively lower light absorption, while at high temperature produces more aromatics hydrocarbons with relatively strong light absorption. The results of this work are helpful to trace the source of brown carbon and optimize biomass energy utilization.
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Affiliation(s)
- Peng Gao
- School of Chemistry Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rule Deng
- School of Chemistry Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Song Jia
- School of Chemistry Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Li
- School of Chemistry Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuefei Wang
- School of Chemistry Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Qian Xing
- College of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, China.
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Liu S, Luo T, Zhou L, Song T, Wang N, Luo Q, Huang G, Jiang X, Zhou S, Qiu Y, Yang F. Vehicle exhausts contribute high near-UV absorption through carbonaceous aerosol during winter in a fast-growing city of Sichuan Basin, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 312:119966. [PMID: 35985435 DOI: 10.1016/j.envpol.2022.119966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/27/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
Carbonaceous aerosols pose significant climatic impact, however, their sources and respective contribution to light absorption vary and remain poorly understood. In this work, filter-based PM2.5 samples were collected in winter of 2021 at three urban sites in Yibin, a fast-growing city in the south of Sichuan Basin, China. The composition characteristics of PM2.5, light absorption and source of carbonaceous aerosol were analyzed. The city-wide average concentration of PM2.5 was 87.4 ± 31.0 μg/m3 in winter. Carbonaceous aerosol was the most abundant species, accounting for 42.5% of the total PM2.5. Source apportionment results showed that vehicular emission was the main source of PM2.5 during winter, contributing 34.6% to PM2.5. The light absorption of black carbon (BC) and brown carbon (BrC) were derived from a simplified two-component model. We apportioned the light absorption of carbonaceous aerosols to BC and BrC using the Least Squares Linear Regression with optimal angstrom absorption exponent of BC (AAEBC). The average absorption of BC and BrC at 405 nm were 51.6 ± 21.5 Mm-1 and 17.7 ± 8.0 Mm-1, respectively, with mean AAEBC = 0.82 ± 0.02. The contribution of BrC to the absorption of carbonaceous reached 26.1% at 405 nm. Based on the PM2.5 source apportionment and the mass absorption cross-section (MAC) value of BrC at 405 nm, vehicle emission was found to be the dominant source of BrC in winter, contributing up to 56.4%. Therefore, vehicle emissions mitigation should be the primary and an effective way to improve atmospheric visibility in this fast-developing city.
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Affiliation(s)
- Song Liu
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Tianzhi Luo
- Yibin Ecological Environment Monitoring Center Station, Sichuan province, Yibin, 644099, China
| | - Li Zhou
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.
| | - Tianli Song
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Ning Wang
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Qiong Luo
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Gang Huang
- Yibin Ecological Environment Monitoring Center Station, Sichuan province, Yibin, 644099, China
| | - Xia Jiang
- Yibin Ecological Environment Monitoring Center Station, Sichuan province, Yibin, 644099, China
| | - Shuhua Zhou
- Yibin Ecological Environment Monitoring Center Station, Sichuan province, Yibin, 644099, China
| | - Yang Qiu
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Fumo Yang
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
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5
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Fang Z, Deng W, Wang X, He Q, Zhang Y, Hu W, Song W, Zhu M, Lowther S, Wang Z, Fu X, Hu Q, Bi X, George C, Rudich Y. Evolution of light absorption properties during photochemical aging of straw open burning aerosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156431. [PMID: 35660611 DOI: 10.1016/j.scitotenv.2022.156431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Straw burning comprises more than 30% of all types of burned biomass in Asia, while the estimation of the emitted aerosols' direct radiative forcing effect suffers from large uncertainties, especially when atmospheric aging processes are considered. In this study, the light absorption properties of primary and aged straw burning aerosols in open fire were characterized at 7 wavelengths ranging from 370 nm to 950 nm in a chamber. The primary rice, corn and wheat straw burning bulk aerosols together had a mass absorption efficiency (MAE) of 2.43 ± 1.36 m2 g-1 at 520 nm and an absorption Ångström exponent (AAE) of 1.93 ± 0.71, while the primary sorghum straw burning bulk aerosols were characterized by a relatively lower MAE of 0.95 ± 0.54 m2 g-1 and a higher AAE of 4.80 ± 0.68. Both the MAE and AAE of primary aerosols can be well parameterized by the (PM-BC)/BC ratio (in wt.). The MAE of black carbon (BC) increased by 11-190% during photoreactions equivalent to 16-60 h of atmospheric aging, which was positively correlated with the (PM-BC)/(BC) ratio. The MAE of organic aerosols first slightly increased or leveled off, and then decreased. Specifically, at 370 nm, the first growth/plateau stage lasted until OH exposure reached 0.47-1.29 × 1011 molecule cm-3 s, and the following period exhibited decay rates of 1.0-2.8 × 10-12 cm3 molecule-1 s-1 against the OH radical, corresponding to half-lives of 46-134 h in a typical ambient condition. During photoreactions, competition among the lensing effect, growth/bleach of organic chromophores, and particle mass and size growth complicated the evolution of the direct radiative forcing effect. It is concluded that rice and corn straw burning aerosols maintained a warming effect after aging, while the cooling effect of fresh sorghum straw burning aerosols increased with aging.
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Affiliation(s)
- Zheng Fang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China; Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Wei Deng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Quanfu He
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel; Institute of Energy and Climate Research, Troposphere, Forschungszentrum Jülich GmbH, Jülich 52425, Germany
| | - Yanli Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Weiwei Hu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Wei Song
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Ming Zhu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Scott Lowther
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Lancaster Environment Centre, Lancaster University, Lancaster LA14YQ, UK
| | - Zhaoyi Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuewei Fu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qihou Hu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Xinhui Bi
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environment Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Christian George
- Institut de Recherches sur la Catalyse et l'Environment de Lyon (IRCELYON), CNRS, UMR5256, Villeurbanne 69626, France
| | - Yinon Rudich
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
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6
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Zhang C, Gao S, Yan F, Kang S, He C, Li C. An overestimation of light absorption of brown carbon in ambient particles caused by using filters with large pore size. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 833:155286. [PMID: 35429555 DOI: 10.1016/j.scitotenv.2022.155286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/30/2022] [Accepted: 04/11/2022] [Indexed: 06/14/2023]
Abstract
As an important component of carbonaceous particles, organic carbon (OC) plays a significant role in radiative forcing in the atmosphere. Recently, the warming effect of light-absorbing OC has been emphasized. Water-soluble organic carbon (WSOC) is commonly used as a surrogate to investigate the light absorption of OC. Thus far, filters with 0.45 μm (PS1) and 0.20 μm pore sizes (PS2) are both used to investigate the light absorption of WSOC, which may cause large divergent results. In this study, we found that the light absorption ability of WSOC treated with PS1 was higher than that of PS2 due to the extinction of suspended particles (e.g., black carbon) with particle size between 0.20 μm and 0.45 μm, although the concentrations of WSOC treated with PS1 and PS2 were very close. This phenomenon was more remarkable at visible wavelengths, resulting in an overestimation of the warming effect of WSOC by 9%-22% for aerosol samples treated by PS1, with the highest values occurring in samples heavily influenced by fossil fuel burning emissions. An overestimation of WSOC light absorption treated by PS1 occurred in the investigated ambient aerosol samples from three sites, so it may be a general phenomenon that also exists in other regions of the world. Therefore, to achieve the actual solar radiative forcing of OC in the atmosphere, it is recommended to use PS2 in the future, and reported data of WSOC treated by PS1 should be re-evaluated.
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Affiliation(s)
- Chao Zhang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shaopeng Gao
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Fangping Yan
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cenlin He
- Research Applications Laboratory, National Center for Atmospheric Research, Boulder, CO 80301, USA
| | - Chaoliu Li
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Gao Y, Wang Q, Li L, Dai W, Yu J, Ding L, Li J, Xin B, Ran W, Han Y, Cao J. Optical properties of mountain primary and secondary brown carbon aerosols in summertime. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150570. [PMID: 34582869 DOI: 10.1016/j.scitotenv.2021.150570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Brown carbon (BrC) can affect atmospheric radiation due to its strong absorption ability from the near ultraviolet to the visible range, thereby influencing global climate. However, given the complexity of BrC's chemical composition, its optical properties are still poorly understood, especially in mountainous areas. In this study, the black carbon (BC) tracer method is used to explore the light-absorbing properties of primary and secondary BrC at Mount Hua, China during the 2018 summer period. The primary BrC absorption contributes to 10-15% of the total BrC absorption at a wavelength of 370 nm. From the positive matrix factorization analysis, traffic emissions are found to be a major source of primary BrC absorption (44%), followed by industry and biomass-burning emissions (29%). The secondary BrC accounts for 87% of the total BrC absorption at a wavelength of 370 nm, indicating that BrC is dominated by secondary formation. The observation of a higher secondary BrC absorption diurnal pattern at Mount Hua can be affected by secondary BrC in the residual layer after sunrise and the formation of light-absorbing chromophores by photochemical oxidation in the afternoon. The estimated average mass absorption efficiencies of primary and secondary BrC (MAE_pri and MAE_sec, respectively) are 0.4 m2/g and 2.1 m2/g at wavelengths of 370 nm, respectively, indicating a stronger light-absorbing ability for secondary BrC than for primary BrC. There is no significant difference in MAE_pri within a daily variation, but the daytime MAE_sec value is higher than that during the night. Our study shows that secondary BrC is important to light absorption in mountainous areas.
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Affiliation(s)
- Yuan Gao
- Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, 519087, China
| | - Qiyuan Wang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Guanzhong Plain Ecological Environment Change and Comprehensive Treatment National Observation and Research Station, China.
| | - Li Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Wenting Dai
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Jinjiang Yu
- Huashan Meteorological Station, Weinan 714000, China
| | - Limin Ding
- Huashan Meteorological Station, Weinan 714000, China
| | - Jianjun Li
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Bo Xin
- Weinan Meteorological Administration, Weinan 714000, China
| | - Weikang Ran
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Yongming Han
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China; Guanzhong Plain Ecological Environment Change and Comprehensive Treatment National Observation and Research Station, China
| | - Junji Cao
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China.
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Kaskaoutis DG, Grivas G, Stavroulas I, Bougiatioti A, Liakakou E, Dumka UC, Gerasopoulos E, Mihalopoulos N. Apportionment of black and brown carbon spectral absorption sources in the urban environment of Athens, Greece, during winter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 801:149739. [PMID: 34467915 DOI: 10.1016/j.scitotenv.2021.149739] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/30/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
This study examines the spectral properties and source characteristics of absorbing aerosols (BC: Black Carbon; BrC: Brown Carbon, based on aethalometer measurements) in the urban background of Athens during December 2016-February 2017. Using common assumptions regarding the spectral dependence of absorption due to BC (AAEBC = 1) and biomass burning (AAEbb = 2), and calculating an optimal AAEff value for the dataset (1.18), the total spectral absorption was decomposed into five components, corresponding to absorption of BC and BrC from fossil-fuel (ff) combustion and biomass burning (bb), and to secondary BrC estimated using the BC-tracer minimum R-squared (MRS) method. Substantial differences in the contribution of various components to the total absorption were found between day and night, due to differences in emissions and meteorological dynamics, while BrC and biomass burning aerosols presented higher contributions at shorter wavelengths. At 370 nm, the absorption due to BCff contributed 36.3% on average, exhibiting a higher fraction (58.1%) during daytime, while the mean BCbb absorption was estimated at 18.4%. The mean absorption contributions due to BrCff, BrCbb and BrCsec were 6.7%, 32.3% and 4.9%, respectively. The AbsBCff,370 component maximized during the morning traffic hours and was strongly correlated with NOx (R2 = 0.76) and CO (R2 = 0.77), while a similar behavior was seen for the AbsBrCff,370 component. AbsBCbb and AbsBrCbb levels escalated during nighttime and were highly associated with nss-K+ and with the organic aerosol (OA) components related to fresh and fast-oxidized biomass burning (BBOA and SV-OOA) as obtained from ACSM measurements. Multiple linear regression was used to attribute BrC absorption to five OA components and to determine their absorption contributions and efficiencies, revealing maximum contributions of BBOA (33%) and SV-OOA (21%). Sensitivity analysis was performed in view of the methodological uncertainties and supported the reliability of the results, which can have important implications for radiative transfer models.
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Affiliation(s)
- D G Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece; Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 001, India.
| | - G Grivas
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece.
| | - I Stavroulas
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece
| | - A Bougiatioti
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece
| | - E Liakakou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece
| | - U C Dumka
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece
| | - E Gerasopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece
| | - N Mihalopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece; Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 001, India
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9
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Ferrero L, Bernardoni V, Santagostini L, Cogliati S, Soldan F, Valentini S, Massabò D, Močnik G, Gregorič A, Rigler M, Prati P, Bigogno A, Losi N, Valli G, Vecchi R, Bolzacchini E. Consistent determination of the heating rate of light-absorbing aerosol using wavelength- and time-dependent Aethalometer multiple-scattering correction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 791:148277. [PMID: 34119780 DOI: 10.1016/j.scitotenv.2021.148277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Accurate and temporally consistent measurements of light absorbing aerosol (LAA) heating rate (HR) and of its source apportionment (fossil-fuel, FF; biomass-burning, BB) and speciation (black and brown Carbon; BC, BrC) are needed to evaluate LAA short-term climate forcing. For this purpose, wavelength- and time-dependent accurate LAA absorption coefficients are required. HR was experimentally determined and apportioned (sources/species) in the EMEP/ACTRIS/COLOSSAL-2018 winter campaign in Milan (urban-background site). Two Aethalometers (AE31/AE33) were installed together with a MAAP, CPC, OPC, a low volume sampler (PM2.5) and radiation instruments. AE31/AE33 multiple-scattering correction factors (C) were determined using two reference systems for the absorption coefficient: 1) 5-wavelength PP_UniMI with low time resolution (12 h, applied to PM2.5 samples); 2) timely-resolved MAAP data at a single wavelength. Using wavelength- and time-independent C values for the AE31 and AE33 obtained with the same reference device, the total HR showed a consistency (i.e. reproducibility) with average values comparable at 95% probability. However, if different reference devices/approaches are used, i.e. MAAP is chosen as reference instead of a PP_UniMI, the HR can be overestimated by 23-30% factor (by both AE31/AE33). This became more evident focusing on HR apportionment: AE33 data (corrected by a wavelength- and time-independent C) showed higher HRFF (+24 ± 1%) and higher HRBC (+10 ± 1%) than that of AE31. Conversely, HRBB and HRBrC were -28 ± 1% and -29 ± 1% lower for AE33 compared to AE31. These inconsistencies were overcome by introducing a wavelength-dependent Cλ for both AE31 and AE33, or using multi-wavelength apportionment methods, highlighting the need for further studies on the influence of wavelength corrections for HR determination. Finally, the temporally-resolved determination of C resulted in a diurnal cycle of the HR not statistically different whatever the source- speciation- apportionment used.
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Affiliation(s)
- L Ferrero
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy.
| | - V Bernardoni
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - L Santagostini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - S Cogliati
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy; Remote Sensing of Environmental Dynamics Lab., DISAT, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano, Italy
| | - F Soldan
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - S Valentini
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - D Massabò
- Dip. di Fisica Università di Genova & INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - G Močnik
- Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia; Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - A Gregorič
- Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia; Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - M Rigler
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - P Prati
- Dip. di Fisica Università di Genova & INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - A Bigogno
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - N Losi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - G Valli
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - R Vecchi
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - E Bolzacchini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
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Wang Q, Wang L, Tao M, Chen N, Lei Y, Sun Y, Xin J, Li T, Zhou J, Liu J, Ji D, Wang Y. Exploring the variation of black and brown carbon during COVID-19 lockdown in megacity Wuhan and its surrounding cities, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 791:148226. [PMID: 34412400 PMCID: PMC8176899 DOI: 10.1016/j.scitotenv.2021.148226] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/28/2021] [Accepted: 05/29/2021] [Indexed: 05/05/2023]
Abstract
Absorbing carbonaceous aerosols, i.e. black and brown carbon (BC and BrC), affected heavily on climate change, regional air quality and human health. The nationwide lockdown measures in 2020 were performed to against the COVID-19 outbreak, which could provide an important opportunity to understand their variations on light absorption, concentrations, sources and formation mechanism of carbonaceous aerosols. The BC concentration in Wuhan megacity (WH) was 1.9 μg m-3 during lockdown, which was 24% lower than those in the medium-sized cities and 26% higher than those in small city; in addition, 39% and 16-23% reductions occurred compared with the same periods in 2019 in WH and other cities, respectively. Fossil fuels from vehicles and industries were the major contributors to BC; and compared with other periods, minimum contribution (64-86%) mainly from fossil fuel to BC occurred during the lockdown in all cities. Secondary BrC (BrCsec) played a major role in the BrC light absorption, accounting for 65-77% in WH during different periods. BrCsec was promoted under high humidity, and decreased through the photobleaching of chromophores under higher Ox. Generally, the lockdown measures reduced the BC concentrations significantly; however, the variation of BrCsec was slight.
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Affiliation(s)
- Qinglu Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lili Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Minghui Tao
- Laboratory of Critical Zone Evolution, School of Geography and Information Engineering, China University of Geosciences, Wuhan 430074, China
| | - Nan Chen
- The Ecology and Environment Monitoring Center of Hubei Province, Wuhan 430070, China
| | - Yali Lei
- Key Lab of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Yang Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China; College of Atmospheric Sciences of Huainan, Institute of Atmospheric Physics, Chinese Academy of Sciences, Huainan 232000, China
| | - Jinyuan Xin
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tingting Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China
| | - Jingxiang Zhou
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingda Liu
- College of Atmospheric Physics, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Dongsheng Ji
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuesi Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
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11
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Dey S, Mukherjee A, Polana AJ, Rana A, Mao J, Jia S, Yadav AK, Khillare PS, Sarkar S. Brown carbon aerosols in the Indo-Gangetic Plain outflow: insights from excitation emission matrix (EEM) fluorescence spectroscopy. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:745-755. [PMID: 33899857 DOI: 10.1039/d1em00050k] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report the first characterization of the aerosol brown carbon (BrC) composition in the Indian context using excitation emission matrix (EEM) fluorescence spectroscopy coupled with parallel factor (PARAFAC) analysis. We find that biomass burning (BB)-dominated wintertime aerosols in the Indo-Gangetic Plain (IGP) outflow are characterized by two humic-like (HULIS) (C1_aq and C2_aq) and one protein-like/fossil fuel-derived (C3_aq) component for aqueous-extractable BrC (BrCaq), and by one humic-like (C1_me) and one protein-like (C2_me) component for methanol-extractable BrC (BrCme). Strong correlations of the BB tracer nss-K+ with C1_aq and C2_aq (r = 0.75-0.84, p < 0.01) and C1_me (r = 0.77, p < 0.01) point towards the BB-dominated IGP outflow as the major source. This is also supported by the analysis of fluorescence indices, which suggest extensive humification of BB emissions during atmospheric transport. The HULIS components correlate significantly with BrC absorption (r = 0.85-0.94, p < 0.01), and contribute substantially to the BrC relative radiative forcing of 13-24% vis-à-vis elemental carbon (EC). There is strong evidence that the abundant BB-derived NOX leads to NO3- formation in the IGP plume and drives the formation of water-soluble nitroaromatics (NACs) that constrain BrCaq light absorption (r = 0.56, p < 0.01) to a considerable degree. Overall, the study uncovers complex atmospheric processing of the IGP outflow in winter, which has important implications for regional climate.
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Affiliation(s)
- Supriya Dey
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, Nadia, India
| | - Arya Mukherjee
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, Nadia, India
| | - Anuraag J Polana
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, Nadia, India
| | - Archita Rana
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, Nadia, India
| | - Jingying Mao
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, PR China
| | - Shiguo Jia
- Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou 510275, PR China and School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Amit K Yadav
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Pandit S Khillare
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sayantan Sarkar
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, Nadia, India and School of Engineering, Indian Institute of Technology (IIT) Mandi, Room No. F8, Building A8, Kamand, Himachal Pradesh 175075, India.
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12
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Dumka UC, Kaskaoutis DG, Mihalopoulos N, Sheoran R. Identification of key aerosol types and mixing states in the central Indian Himalayas during the GVAX campaign: the role of particle size in aerosol classification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143188. [PMID: 33143923 DOI: 10.1016/j.scitotenv.2020.143188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/15/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
Studies in aerosol properties, types and sources in the Himalayas are important for atmospheric and climatic issues due to high aerosol loading in the neighboring plains. This study uses in situ measurements of aerosol optical and microphysical properties obtained during the Ganges Valley Aerosol eXperiment (GVAX) at Nainital, India over the period June 2011-March 2012, aiming to identify key aerosol types and mixing states for two particle sizes (PM1 and PM10). Using a classification matrix based on SAE vs. AAE thresholds (scattering vs. absorption Ångström exponents, respectively), seven aerosol types are identified, which are highly dependent on particle size. An aerosol type named "large/BC mix" dominates in both PM1 (45.4%) and PM10 (46.9%) mass, characterized by aged BC mixed with other aerosols, indicating a wide range of particle sizes and mixing states. Small particles with low spectral dependence of the absorption (AAE < 1) account for 31.6% and BC-dominated aerosols for 14.8% in PM1, while in PM10, a large fraction (39%) corresponds to "large/low-absorbing" aerosols and only 3.9% is characterized as "BC-dominated". The remaining types consist of mixtures of dust and local emissions from biofuel burning and display very small fractions. The main optical properties e.g. spectral scattering, absorption, single scattering albedo, activation ratio, as well as seasonality and dependence on wind speed and direction of identified types are examined, revealing a large influence of air masses originating from the Indo-Gangetic Plains. This indicates that aerosols over the central Himalayas are mostly composed by mixtures of processed and transported polluted plumes from the plains. This is the first study that identifies key aerosol populations in the central Indian Himalayas based on in situ measurements and the results are highly important for aerosol-type inventories, chemical transport models and reducing the uncertainty in aerosol radiative forcing over the third pole.
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Affiliation(s)
- U C Dumka
- Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 001, India.
| | - D G Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece.
| | - N Mihalopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece
| | - Rahul Sheoran
- Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 001, India
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13
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Choudhary V, Rajput P, Gupta T. Absorption properties and forcing efficiency of light-absorbing water-soluble organic aerosols: Seasonal and spatial variability. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 272:115932. [PMID: 33248827 DOI: 10.1016/j.envpol.2020.115932] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 10/25/2020] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
Light-absorbing organic aerosols, also known as brown carbon (BrC), enhance the warming effect of the Earth's atmosphere. The seasonal and spatial variability of BrC absorption properties is poorly constrained and accounted for in the climate models resulting in a substantial underestimation of their radiative forcing estimates. This study reports seasonal and spatial variability of absorption properties and simple forcing efficiency of light-absorbing water-soluble organic carbon (WSOC, SFEWSOC) by utilizing current and previous field-based measurements reported mostly from Asia along with a few observations from Europe, the USA, and the Amazon rainforest. The absorption coefficient of WSOC at 365 nm (babs-365) and the concentrations of carbonaceous species at Kanpur were about an order of magnitude higher during winter than in the monsoon season owing to differences in the boundary layer height, active sources and their strengths, and amount of seasonal wet precipitation. The WSOC aerosols during winter exhibited ∼1.6 times higher light absorption capacity than in the monsoon season at Kanpur site. The assessment of spatial variability of the imaginary component of the refractive index spectrum (kλ) across South Asia has revealed that it varies from ∼1 to 2 orders of magnitude and light absorption capacity of WSOC ranges from 3 to 21 W/g. The light absorption capacity of WSOC aerosols exhibited less spatial variability across East Asia (5-13 W/g) when compared to that in the South Asia. The photochemical aging of WSOC aerosols, indicated by the enhancement in WSOC/OC ratio, was linked to degradation in their light absorption capacity, whereas the absorption Ångström exponent (AAE) remained unaffected. This study recommends the adoption of refined climate models where sampling regime specific absorption properties are calculated separately, such that these inputs can better constrain the model estimates of the global effects of BrC.
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Affiliation(s)
- Vikram Choudhary
- Department of Civil Engineering and APTL at Center for Environmental Science and Engineering (CESE), Indian Institute of Technology Kanpur, Kanpur, 208 016, India.
| | - Prashant Rajput
- Centre for Environmental Health (CEH), Public Health Foundation of India, Gurugram, Haryana, 122002, India
| | - Tarun Gupta
- Department of Civil Engineering and APTL at Center for Environmental Science and Engineering (CESE), Indian Institute of Technology Kanpur, Kanpur, 208 016, India
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14
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Bikkina P, Bikkina S, Kawamura K, Sudheer AK, Mahesh G, Kumar SK. Evidence for brown carbon absorption over the Bay of Bengal during the southwest monsoon season: a possible oceanic source. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:1743-1758. [PMID: 32686798 DOI: 10.1039/d0em00111b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The near UV-visible light-absorbing organic carbon (OC) of ambient aerosols, referred to here as brown carbon (BrC), significantly influences the atmospheric radiative forcing on both regional and global scales. Here, we documented BrC absorption in the aqueous and methanol extracts of marine aerosols collected over the Bay of Bengal (BoB: September-October 2017) and a city, Visakhapatnam (May-June 2018), in southern India during the southwest monsoon (i.e., a transition period with weak continental impact). The absorption spectra of BrC over the BoB showed several peaks around 300-400 nm and differ from those observed over Visakhapatnam. The absorption coefficient of BrC over the BoB, unlike Visakhapatnam data, does not seem to covary with other chemical proxies of biomass burning (non-sea-salt or nss-K+) and coal combustion (nss-SO42-) in the continental outflows, suggesting a different source of BrC over the BoB. Besides, we observed higher proportions of water-insoluble organic carbon (WIOC/OC: 0.89 ± 0.02) and significant enrichment of Mg2+ over Na+ (i.e., relative to seawater) in BoB aerosols. This result and the backward air mass trajectories both hinted their major source of OC from marine-derived organic matter. In contrast, the absorption spectra of BrC over Visakhapatnam are like those from biomass burning emissions in the Indo-Gangetic Plain. This observation is further supported by the satellite-based fire counts and backward air mass trajectories. Therefore, our study underscores the BrC aerosols from the oceanic sources and southern India, hitherto unknown, and can improve our understanding of the regional climate effects of carbonaceous aerosols if included in models.
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Affiliation(s)
- Poonam Bikkina
- National Institute of Oceanography, Regional Centre Waltair, Visakhapatnam, Andhra Pradesh 530017, India.
| | - Srinivas Bikkina
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - Kimitaka Kawamura
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - A K Sudheer
- Geosciences Division, Physical Research Laboratory, Ahmedabad, India
| | - G Mahesh
- Geosciences Division, Physical Research Laboratory, Ahmedabad, India
| | - S Kuswanth Kumar
- National Institute of Oceanography, Regional Centre Waltair, Visakhapatnam, Andhra Pradesh 530017, India. and University of Hyderabad, Hyderabad 500 046, Telangana State, India
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15
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Yan F, Kang S, Sillanpää M, Hu Z, Gao S, Chen P, Gautam S, Reinikainen SP, Li C. A new method for extraction of methanol-soluble brown carbon: Implications for investigation of its light absorption ability. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 262:114300. [PMID: 32155553 DOI: 10.1016/j.envpol.2020.114300] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/28/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
As an important component of organic carbon (OC), brown carbon (BrC) plays a significant role in radiative forcing in the atmosphere. Water-insoluble OC (WIOC) generally has higher light absorption ability than water-soluble OC (WSOC). The mass absorption cross-section (MAC) of WIOC is normally investigated by dissolving OC in methanol. However, all the current methods have shortcomings due to neglecting the methanol insoluble particulate carbon that is detached from the filter and suspended in methanol extracts, which results in MAC uncertainties of the methanol-soluble BrC and its climate warming estimation. In this study, by investigating typical biomass combustion sourced aerosols from the Tibetan Plateau and ambient aerosols from rural and urban areas in China, we evaluated the light absorption of extractable OC fraction for the existing methods. Moreover, a new method was developed to overcome the methanol insoluble particulate carbon detachment problem to achieve more reliable MAC values. We found that OC can be dissolved in methanol in a short time (e.g., 1 h) and ultrasonic treatment and long-term soaking do not significantly increase the extractable OC fraction. Additionally, we proved that methanol insoluble particulate carbon detachment in methanol does exist in previous methods, causing overestimation of the BrC mass extracted by methanol and thus the underestimation of MAC values. We therefore recommend the newly developed extraction method in this study to be utilized in future related studies to quantitatively obtain the light absorption property of methanol-soluble BrC.
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Affiliation(s)
- Fangping Yan
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; LUT School of Engineering Science, Lappeenranta University of Technology, P.O. Box 20, 53851, Lappeenranta, Finland; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mika Sillanpää
- Department of Civil and Environmental Engineering, Floride International University, Miami, FI, USA
| | - Zhaofu Hu
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shaopeng Gao
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Sangita Gautam
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Satu-Pia Reinikainen
- LUT School of Engineering Science, Lappeenranta University of Technology, P.O. Box 20, 53851, Lappeenranta, Finland
| | - Chaoliu Li
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China.
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16
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Mandariya AK, Tripathi SN, Gupta T, Mishra G. Wintertime hygroscopic growth factors (HGFs) of accumulation mode particles and their linkage to chemical composition in a heavily polluted urban atmosphere of Kanpur at the Centre of IGP, India: Impact of ambient relative humidity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 704:135363. [PMID: 31837851 DOI: 10.1016/j.scitotenv.2019.135363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/14/2019] [Accepted: 11/01/2019] [Indexed: 06/10/2023]
Abstract
This study reported results of the wintertime simultaneous measurements of hygroscopic growth factors (HGFs) and particle-phase chemical composition of accumulation mode particles using a self-assembled Hygroscopic Tandem Differential Mobility Analyzer (H-TDMA) and an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS), respectively at a heavily polluted urban atmosphere of Kanpur, situated in the center of IGP in India. HGFs at 85% relative humidity (RH) and the size-resolved composition of ambient aerosol particles (dry electrical mobility diameters of 100 and 150 nm) were investigated. HGF_85% was found to increase with particle size. The relative mass fraction of organic aerosol (OA) and NH4NO3 are probably the major contributors to the fluctuation of the HGF_85% for both particle sizes. The HGF_85% of accumulation mode particles were observed to increase from the minimum value observed during the morning until its maximum afternoon value. This study reported two maximum (early morning and afternoon time) and two minimum values (morning and evening time) of HGF_85%s. As a consequence, the main reasons for this incremental behavior were, increase in the ratio of inorganic to OA and oxidation level, f44 (m/z44/OA) of the OA within the particle phase. In context to the effect of ambient RH, this study reported two distinct variations of mean HGF_85% as the function of ambient RH. The positive linear relationship at low RH (LRH, RH ≤ 50%) was clearly associated with low OA loading, relatively higher substantial temperature, and wind speed. We also observed increment in f44, and effective density indicating aging of aerosol. However, HGF_85% was found to inversely decline as a function of RH at higher RH (HRH, RH > 50%) conditions, which clearly reflect the more significant contribution of primary OA and lower oxidation level of OA. Our results show the declining trend in size-resolved effective density at HRH conditions, confirming the above conclusions.
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Affiliation(s)
| | - S N Tripathi
- Department of Civil Engineering, Indian Institute of Technology, Kanpur, India; Centre for Environmental Science and Engineering, CESE, IIT Kanpur, India.
| | - Tarun Gupta
- Department of Civil Engineering, Indian Institute of Technology, Kanpur, India; Centre for Environmental Science and Engineering, CESE, IIT Kanpur, India
| | - Gaurav Mishra
- Nuclear Engineering and Technology Programme, Department of Mechanical Engineering, IIT Kanpur, India
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17
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Carbonaceous Aerosols in Contrasting Atmospheric Environments in Greek Cities: Evaluation of the EC-tracer Methods for Secondary Organic Carbon Estimation. ATMOSPHERE 2020. [DOI: 10.3390/atmos11020161] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This study examines the carbonaceous-aerosol characteristics at three contrasting urban environments in Greece (Ioannina, Athens, and Heraklion), on the basis of 12 h sampling during winter (January to February 2013), aiming to explore the inter-site differences in atmospheric composition and carbonaceous-aerosol characteristics and sources. The winter-average organic carbon (OC) and elemental carbon (EC) concentrations in Ioannina were found to be 28.50 and 4.33 µg m−3, respectively, much higher than those in Heraklion (3.86 µg m−3 for OC and 2.29 µg m−3 for EC) and Athens (7.63 µg m−3 for OC and 2.44 µg m−3 for EC). The winter OC/EC ratio in Ioannina (6.53) was found to be almost three times that in Heraklion (2.03), indicating a larger impact of wood combustion, especially during the night, whereas in Heraklion, emissions from biomass burning were found to be less intense. Estimations of primary and secondary organic carbon (POC and SOC) using the EC-tracer method, and specifically its minimum R-squared (MRS) variant, revealed large differences between the sites, with a prevalence of POC (67–80%) in Ioannina and Athens and with a larger SOC fraction (53%) in Heraklion. SOC estimates were also obtained using the 5% and 25% percentiles of the OC/EC data to determine the (OC/EC)pri, leading to results contrasting to the MRS approach in Ioannina (70–74% for SOC). Although the MRS method provides generally more robust results, it may significantly underestimate SOC levels in environments highly burdened by biomass burning, as the fast-oxidized semi-volatile OC associated with combustion sources is classified in POC. Further analysis in Athens revealed that the difference in SOC estimates between the 5% percentile and MRS methods coincided with the semi-volatile oxygenated organic aerosol as quantified by aerosol mass spectrometry. Finally, the OC/Kbb+ ratio was used as tracer for decomposition of the POC into fossil-fuel and biomass-burning components, indicating the prevalence of biomass-burning POC, especially in Ioannina (77%).
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18
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Bikkina S, Sarin M. Brown carbon in the continental outflow to the North Indian Ocean. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:970-987. [PMID: 31089643 DOI: 10.1039/c9em00089e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this paper, we synthesize the size distribution and optical properties of the atmospheric water-soluble fraction of light-absorbing organic carbon (brown carbon; BrC) in the continental outflow from the Indo-Gangetic Plain (IGP) in South Asia to the North Indian Ocean. A comparison of the mass absorption coefficient of water-soluble BrC (babs-WSBrC-365nm) in PM2.5 with that in PM10 sampled over the Bay of Bengal reveals the dominance of BrC in fine mode. Furthermore, the babs-BrC-365nm shows a significant linear relationship with mass concentrations of airborne particulate matter, water-soluble organic carbon and non-sea-salt-K+ in the continental outflow from the IGP. This observation emphasizes the ubiquitous nature and significant contribution of water-soluble BrC from biomass burning emissions (BBEs). Comparing the absorption properties from this study with global datasets, it is discernible that BBEs dominate BrC absorption. Furthermore, the imaginary refractive index of water-soluble BrC (kWSBrC-365nm) in marine aerosols sampled over the North Indian Ocean during November is significantly higher than during December to January. Thus, significant temporal variability is associated with crop-residue burning emissions in the IGP on the composition of BrC over the North Indian Ocean. Our estimates show that the babs-WSBrC-365nm and kWSBrC-365nm from post-harvest crop-residue burning emissions in the IGP are much higher than the BBEs from the southeastern United States and Amazonian forest fires. Another major finding of this study is the lack of significant relationship between kWSBrC-365nm and the mass ratio of elemental carbon to particulate organic matter, as previously suggested by chamber experiments to model varying BrC absorption properties in ambient aerosols. Therefore, considerable spatio-temporal variability prevails among emission sources (wood burning vs. crop-residue burning), which needs to be considered when assessing the regional radiative forcing of BrC relative to major absorbing elemental carbon.
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Affiliation(s)
- Srinivas Bikkina
- Geosciences Division, Physical Research Laboratory, Ahmedabad-380 009, India.
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19
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Khobragade R, Singh SK, Shukla PC, Gupta T, Al-Fatesh AS, Agarwal AK, Labhasetwar NK. Chemical composition of diesel particulate matter and its control. CATALYSIS REVIEWS-SCIENCE AND ENGINEERING 2019. [DOI: 10.1080/01614940.2019.1617607] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Rohini Khobragade
- Energy and Resource Management Division, CSIR-National Environmental Engineering Research Institute, Nagpur, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur, India
| | - Sunit Kumar Singh
- Energy and Resource Management Division, CSIR-National Environmental Engineering Research Institute, Nagpur, India
| | | | - Tarun Gupta
- Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, India
| | - Ahmed S. Al-Fatesh
- Chemical Engineering Department, College of Engineering, King Saud University, Riyadh, Saudi Arabia
| | - Avinash Kumar Agarwal
- Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur, India
| | - Nitin K. Labhasetwar
- Energy and Resource Management Division, CSIR-National Environmental Engineering Research Institute, Nagpur, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur, India
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20
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Wu G, Ram K, Fu P, Wang W, Zhang Y, Liu X, Stone EA, Pradhan BB, Dangol PM, Panday AK, Wan X, Bai Z, Kang S, Zhang Q, Cong Z. Water-Soluble Brown Carbon in Atmospheric Aerosols from Godavari (Nepal), a Regional Representative of South Asia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3471-3479. [PMID: 30848122 DOI: 10.1021/acs.est.9b00596] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Brown carbon (BrC) has recently emerged as an important light-absorbing aerosol. This study provides interannual and seasonal variations in light absorption properties, chemical composition, and sources of water-soluble BrC (WS-BrC) based on PM10 samples collected in Godavari, Nepal, from April 2012 to May 2014. The mass absorption efficiency of WS-BrC at 365 nm (MAE365) shows a clear seasonal variability, with the highest MAE365 of 1.05 ± 0.21 m2 g-1 in premonsoon season and the lowest in monsoon season (0.59 ± 0.16 m2 g-1). The higher MAE365 values in nonmonsoon seasons are associated with fresh biomass burning emissions. This is further substantiated by a strong correlation ( r = 0.79, P < 0.01) between Abs365 (light absorption coefficient at 365 nm) and levoglucosan. We found, using fluorescence techniques, that humic-like and protein-like substances are the main chromophores in WS-BrC and responsible for 80.2 ± 4.1% and 19.8 ± 4.1% of the total fluorescence intensity, respectively. BrC contributes to 8.78 ± 3.74% of total light absorption over the 300-700 nm wavelength range. Considering the dominant contribution of biomass burning to BrC over Godavari, this study suggests that reduction in biomass burning emission may be a practical method for climate change mitigation in South Asia.
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Affiliation(s)
- Guangming Wu
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes , Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing 100101 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Kirpa Ram
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes , Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing 100101 , China
- Institute of Environment and Sustainable Development , Banaras Hindu University , Varanasi 221005 , India
| | - Pingqing Fu
- Institute of Surface-Earth System Science , Tianjin University , Tianjin 300072 , China
| | - Wan Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment , Chinese Research Academy of Environmental Sciences , Beijing 100012 , China
| | - Yanlin Zhang
- Yale-NUIST Center on Atmospheric Environment , Nanjing University of Information Science and Technology , Nanjing 210044 , China
| | - Xiaoyan Liu
- Yale-NUIST Center on Atmospheric Environment , Nanjing University of Information Science and Technology , Nanjing 210044 , China
| | - Elizabeth A Stone
- Department of Chemistry , University of Iowa , Iowa City , Iowa 52246 , United States
| | - Bidya Banmali Pradhan
- International Centre for Integrated Mountain Development , Khumaltar , Lalitpur 009771 , Nepal
| | - Pradeep Man Dangol
- International Centre for Integrated Mountain Development , Khumaltar , Lalitpur 009771 , Nepal
| | - Arnico K Panday
- International Centre for Integrated Mountain Development , Khumaltar , Lalitpur 009771 , Nepal
| | - Xin Wan
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes , Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing 100101 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Zhipeng Bai
- State Key Laboratory of Environmental Criteria and Risk Assessment , Chinese Research Academy of Environmental Sciences , Beijing 100012 , China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources , Chinese Academy of Sciences , Lanzhou 730000 , China
- Center for Excellence in Tibetan Plateau Earth Sciences , Chinese Academy of Sciences , Beijing 100101 , China
| | - Qianggong Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes , Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing 100101 , China
- Center for Excellence in Tibetan Plateau Earth Sciences , Chinese Academy of Sciences , Beijing 100101 , China
| | - Zhiyuan Cong
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes , Institute of Tibetan Plateau Research, Chinese Academy of Sciences , Beijing 100101 , China
- Center for Excellence in Tibetan Plateau Earth Sciences , Chinese Academy of Sciences , Beijing 100101 , China
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21
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Chemical Composition of Aerosol over the Arctic Ocean from Summer ARctic EXpedition (AREX) 2011–2012 Cruises: Ions, Amines, Elemental Carbon, Organic Matter, Polycyclic Aromatic Hydrocarbons, n-Alkanes, Metals, and Rare Earth Elements. ATMOSPHERE 2019. [DOI: 10.3390/atmos10020054] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During the summers of 2011 and 2012, two scientific cruises were carried out over the Arctic Ocean aiming at the determination of the aerosol chemical composition in this pristine environment. First, mass spectrometry was applied to study the concentration and gas/particle partitioning of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes. Experimental and modelled data of phase partitioning were compared: results demonstrated an equilibrium between gas and particle phase for PAHs, while n-alkanes showed a particle-oriented partitioning, due to the local marine origin of them, confirmed by the extremely low value of their carbon preference index. Moreover, the inorganic and organic ions (carboxylic acids and amines) concentrations, together with those of elemental carbon (EC) and organic matter (OM), were analyzed: 63% of aerosol was composed of ionic compounds (>90% from sea-salt) and the OM content was very high (30.5%; close to 29.0% of Cl−) in agreement with n-alkanes’ marine signature. Furthermore, the amines’ (dimethylamine, trimethylamine, diethylamine) concentrations were 3.98 ± 1.21, 1.70 ± 0.82, and 1.06 ± 0.56 p.p.t.v., respectively, fully in keeping with concentration values used in the CLOUD (Cosmics Leaving OUtdoor Droplet)-chamber experiments to simulate the ambient nucleation rate in a H2SO4-DMA-H2O system, showing the amines’ importance in polar regions to promote new particle formation. Finally, high resolution mass spectrometry was applied to determine trace elements, including Rare Earth Elements (REEs), highlighting the dominant natural versus anthropic inputs for trace metals (e.g., Fe, Mn, Ti vs. As, Cd, Ni) and possible signatures of such anthropic activity.
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22
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Weagle CL, Snider G, Li C, van Donkelaar A, Philip S, Bissonnette P, Burke J, Jackson J, Latimer R, Stone E, Abboud I, Akoshile C, Anh NX, Brook JR, Cohen A, Dong J, Gibson MD, Griffith D, He KB, Holben BN, Kahn R, Keller CA, Kim JS, Lagrosas N, Lestari P, Khian YL, Liu Y, Marais EA, Martins JV, Misra A, Muliane U, Pratiwi R, Quel EJ, Salam A, Segev L, Tripathi SN, Wang C, Zhang Q, Brauer M, Rudich Y, Martin RV. Global Sources of Fine Particulate Matter: Interpretation of PM 2.5 Chemical Composition Observed by SPARTAN using a Global Chemical Transport Model. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11670-11681. [PMID: 30215246 DOI: 10.1021/acs.est.8b01658] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Exposure to ambient fine particulate matter (PM2.5) is a leading risk factor for the global burden of disease. However, uncertainty remains about PM2.5 sources. We use a global chemical transport model (GEOS-Chem) simulation for 2014, constrained by satellite-based estimates of PM2.5 to interpret globally dispersed PM2.5 mass and composition measurements from the ground-based surface particulate matter network (SPARTAN). Measured site mean PM2.5 composition varies substantially for secondary inorganic aerosols (2.4-19.7 μg/m3), mineral dust (1.9-14.7 μg/m3), residual/organic matter (2.1-40.2 μg/m3), and black carbon (1.0-7.3 μg/m3). Interpretation of these measurements with the GEOS-Chem model yields insight into sources affecting each site. Globally, combustion sectors such as residential energy use (7.9 μg/m3), industry (6.5 μg/m3), and power generation (5.6 μg/m3) are leading sources of outdoor global population-weighted PM2.5 concentrations. Global population-weighted organic mass is driven by the residential energy sector (64%) whereas population-weighted secondary inorganic concentrations arise primarily from industry (33%) and power generation (32%). Simulation-measurement biases for ammonium nitrate and dust identify uncertainty in agricultural and crustal sources. Interpretation of initial PM2.5 mass and composition measurements from SPARTAN with the GEOS-Chem model constrained by satellite-based PM2.5 provides insight into sources and processes that influence the global spatial variation in PM2.5 composition.
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Affiliation(s)
- Crystal L Weagle
- Department of Chemistry , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Graydon Snider
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Chi Li
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Aaron van Donkelaar
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Sajeev Philip
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
- NASA Ames Research Center , Moffett Field , California 94035-0001 , United States
| | - Paul Bissonnette
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Jaqueline Burke
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - John Jackson
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Robyn Latimer
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Emily Stone
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Ihab Abboud
- Centre for Atmospheric Research Experiments , Environment and Climate Change Canada , Egbert , Ontario L0L 1N0 , Canada
| | | | - Nguyen Xuan Anh
- Institute of Geophysics , Vietnam Academy of Science and Technology , Hanoi , Vietnam
| | - Jeffrey Robert Brook
- Department of Public Health Sciences , University of Toronto , Toronto , Ontario M5S 1A8 , Canada
| | - Aaron Cohen
- Health Effects Institute , Boston , Massachusetts 02110-1817 , United States
| | - Jinlu Dong
- Department of Earth System Science , Tsinghua University , Beijing 100084 , China
| | - Mark D Gibson
- Department of Civil and Resource Engineering , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Derek Griffith
- Council for Scientific and Industrial Research (CSIR) , Pretoria , South Africa 0001
| | - Kebin B He
- Department of Earth System Science , Tsinghua University , Beijing 100084 , China
| | - Brent N Holben
- Earth Science Division , NASA Goddard Space Flight Center , Greenbelt , Maryland 21046 , United States
| | - Ralph Kahn
- Earth Science Division , NASA Goddard Space Flight Center , Greenbelt , Maryland 21046 , United States
| | - Christoph A Keller
- Universities Space Research Association/Goddard Earth Science Technology and Research , Columbia , Maryland 20771 , United States
- Global Modeling and Assimilation Office , NASA Goddard Space Flight Center , Greenbelt , Maryland 20771 , United States
| | - Jong Sung Kim
- Department of Community Health and Epidemiology , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
| | - Nofel Lagrosas
- Manila Observatory , Ateneo de Manila University campus , Quezon City , 1108 , Philippines
| | - Puji Lestari
- Faculty of Civil and Environmental Engineering , ITB , JL. Ganesha No.10 , Bandung 40132 , Indonesia
| | - Yeo Lik Khian
- Center for Global Change Science , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Yang Liu
- Rollins School of Public Health , Emory University , Atlanta , Georgia 30322 , United States
| | - Eloise A Marais
- School of Geography, Earth and Environmental Sciences , University of Birmingham , Birmingham B15 2TT , United Kingdom
| | - J Vanderlei Martins
- Department of Physics and Joint Center for Earth Systems Technology , University of Maryland , Baltimore County , Baltimore , Maryland 21201 , United States
| | - Amit Misra
- Center for Environmental Science and Engineering , Indian Institute of Technology Kanpur , Kanpur , 208016 , India
| | - Ulfi Muliane
- Faculty of Civil and Environmental Engineering , ITB , JL. Ganesha No.10 , Bandung 40132 , Indonesia
| | - Rizki Pratiwi
- Faculty of Civil and Environmental Engineering , ITB , JL. Ganesha No.10 , Bandung 40132 , Indonesia
| | - Eduardo J Quel
- UNIDEF (CITEDEF-CONICET) Juan B. de la Salle 4397 - Villa Martelli , Buenos Aires B1603ALO , Argentina
| | - Abdus Salam
- Department of Chemistry , University of Dhaka , Dhaka 1000 , Bangladesh
| | - Lior Segev
- Department of Earth and Planetary Sciences , Weizmann Institute , Rehovot 76100 , Israel
| | - Sachchida N Tripathi
- Center for Environmental Science and Engineering , Indian Institute of Technology Kanpur , Kanpur , 208016 , India
| | - Chien Wang
- Center for Global Change Science , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Qiang Zhang
- Department of Earth System Science , Tsinghua University , Beijing 100084 , China
| | - Michael Brauer
- School of Population and Public Health , University of British Columbia , Vancouver , British Columbia V6T 1Z2 , Canada
| | - Yinon Rudich
- Department of Earth and Planetary Sciences , Weizmann Institute , Rehovot 76100 , Israel
| | - Randall V Martin
- Department of Chemistry , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
- Department of Physics and Atmospheric Science , Dalhousie University , Halifax , Nova Scotia B3H 4R2 , Canada
- Harvard-Smithsonian Center for Astrophysics , Cambridge , Massachusetts 02138 , United States
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23
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Ferrero L, Močnik G, Cogliati S, Gregorič A, Colombo R, Bolzacchini E. Heating Rate of Light Absorbing Aerosols: Time-Resolved Measurements, the Role of Clouds, and Source Identification. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3546-3555. [PMID: 29474062 DOI: 10.1021/acs.est.7b04320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Light absorbing aerosols (LAA) absorb sunlight and heat the atmosphere. This work presents a novel methodology to experimentally quantify the heating rate (HR) induced by LAA into an atmospheric layer. Multiwavelength aerosol absorption measurements were coupled with spectral measurements of the direct, diffuse and surface reflected radiation to obtain highly time-resolved measurements of HR apportioned in the context of LAA species (black carbon, BC; brown carbon, BrC; dust), sources (fossil fuel, FF; biomass burning, BB), and as a function of cloudiness. One year of continuous and time-resolved measurements (5 min) of HR were performed in the Po Valley. We experimentally determined (1) the seasonal behavior of HR (winter 1.83 ± 0.02 K day-1; summer 1.04 ± 0.01 K day-1); (2) the daily cycle of HR (asymmetric, with higher values in the morning than in the afternoon); (3) the HR in different sky conditions (from 1.75 ± 0.03 K day-1 in clear sky to 0.43 ± 0.01 K day-1 in complete overcast); (4) the apportionment to different sources: HRFF (0.74 ± 0.01 K day-1) and HRBB (0.46 ± 0.01 K day-1); and (4) the HR of BrC (HRBrC: 0.15 ± 0.01 K day-1, 12.5 ± 0.6% of the total) and that of BC (HRBC: 1.05 ± 0.02 K day-1; 87.5 ± 0.6% of the total).
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Affiliation(s)
- Luca Ferrero
- POLARIS Research Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
| | - Griša Močnik
- Aerosol d.o.o. , Kamniška 41 , SI-1000 Ljubljana , Slovenia
- Department of Condensed Matter Physics , Jozef Stefan Institute , Jamova 39 , SI-1000 Ljubljana , Slovenia
| | - Sergio Cogliati
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- Remote Sensing of Environmental Dynamics Lab., Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
| | - Asta Gregorič
- Aerosol d.o.o. , Kamniška 41 , SI-1000 Ljubljana , Slovenia
- Center for Atmospheric Research , University of Nova Gorica , SI-5000 Nova Gorica , Slovenia
| | - Roberto Colombo
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- Remote Sensing of Environmental Dynamics Lab., Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
| | - Ezio Bolzacchini
- POLARIS Research Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
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24
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Cheng Y, He KB, Engling G, Weber R, Liu JM, Du ZY, Dong SP. Brown and black carbon in Beijing aerosol: Implications for the effects of brown coating on light absorption by black carbon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1047-1055. [PMID: 28511349 DOI: 10.1016/j.scitotenv.2017.05.061] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/27/2017] [Accepted: 05/06/2017] [Indexed: 05/08/2023]
Abstract
Brown carbon (BrC) is increasingly included in climate models as an emerging category of particulate organic compounds that can absorb solar radiation efficiently at specific wavelengths. Water-soluble organic carbon (WSOC) has been commonly used as a surrogate for BrC; however, it only represents a limited fraction of total organic carbon (OC) mass, which could be as low as about 20% in urban atmosphere. Using methanol as the extraction solvent, up to approximately 90% of the OC in Beijing aerosol was isolated and measured for absorption spectra over the ultraviolet-to-visible wavelength range. Compared to methanol-soluble OC (MSOC), WSOC underestimated BrC absorption by about 50% at 365nm. The mass absorption efficiencies measured for BrC in Beijing aerosol were converted to the imaginary refractive indices of BrC and subsequently used to compute BrC coating-induced enhancement of light absorption (Eabs) by black carbon. Eabs attributed to lensing was reduced in the case of BrC coating relative to that caused by purely-scattering coating. However, this reduction was overwhelmed by the effect of BrC shell absorption, indicating that the overall effect of BrC coating was an increase in Eabs. Methanol extraction significantly reduced charring of OC during thermal-optical analysis, leading to a large increase in the measured elemental carbon (EC) mass and an apparent improvement in the consistency of EC measurements by different thermal-optical methods.
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Affiliation(s)
- Yuan Cheng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China.
| | - Ke-Bin He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China.
| | - Guenter Engling
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV, USA
| | - Rodney Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jiu-Meng Liu
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA.
| | - Zhen-Yu Du
- National Research Center for Environmental Analysis and Measurement (CNEAC), Beijing, China.
| | - Shu-Ping Dong
- National Research Center for Environmental Analysis and Measurement (CNEAC), Beijing, China
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25
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Chakraborty A, Rajeev P, Rajput P, Gupta T. Water soluble organic aerosols in indo gangetic plain (IGP): Insights from aerosol mass spectrometry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1573-1582. [PMID: 28535589 DOI: 10.1016/j.scitotenv.2017.05.142] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/16/2017] [Accepted: 05/16/2017] [Indexed: 06/07/2023]
Abstract
Filter samples collected during winter of 2015-16 from two polluted urban locations (Allahabad and Kanpur) residing within Indo-Gangetic plain (IGP) showed high levels of water-soluble organic aerosols (WSOA). Total organic aerosols (OA) in submicron fraction, measured at Kanpur in real time via Aerosol Mass Spectrometer also showed substantially high concentration levels. WSOA to OA contribution in Kanpur was found to be very high (around 55%) indicating significant contributions from secondary OA (SOA). On average, WSOA oxidation ratio (O/C) was found to be higher (15-20%) in Kanpur than at Allahabad. WSOA from Allahabad was found to be following a much shallower slope (-0.38) in Van Krevelen diagram (H/C vs O/C plot) than Kanpur (-0.58). These differences suggest different composition and chemistry of WSOA at these two different locations. O/C ratios of WSOA were found to be much higher (~40%) than that of OA and independent of WSOA loading. Higher OA loadings were found to be associated with less oxidized primary OAs (POA) and culminated into lower WSOA/OA ratios. The presence of organo sulfate in filter samples from both locations indicate a significant amount of aqueous processing of organics. Concentrations and characteristics of water insoluble OA (WIOA) in Kanpur revealed that although they are present in significant quantity, their oxidation levels are much (almost 3 times) lower than that of WSOA. This finding indicates that less oxidized OAs are less soluble in line with the conventional wisdom. This study provides the first insight into oxidation levels and evolution of WSOA from India and also explores the interplay between WSOA and OA characteristics based on AMS measurements.
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Affiliation(s)
| | - Pradhi Rajeev
- Department of Civil Engineering, Indian Institute of Technology Kanpur, India
| | - Prashant Rajput
- Department of Civil Engineering, Indian Institute of Technology Kanpur, India
| | - Tarun Gupta
- Department of Civil Engineering, Indian Institute of Technology Kanpur, India; Centre for Environmental Science and Engineering, Indian Institute of Technology Kanpur, India.
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Satish R, Shamjad P, Thamban N, Tripathi S, Rastogi N. Temporal Characteristics of Brown Carbon over the Central Indo-Gangetic Plain. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6765-6772. [PMID: 28520413 DOI: 10.1021/acs.est.7b00734] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Recent global models estimate that light absorption by brown carbon (BrC) in several regions of the world is ∼30-70% of that due to black carbon (BC). It is, therefore, important to understand its sources and characteristics on temporal and spatial scales. In this study, we conducted semicontinuous measurements of water-soluble organic carbon (WSOC) and BrC using particle-into-liquid sampler coupled with a liquid waveguide capillary cell and total organic carbon analyzer (PILS-LWCC-TOC) over Kanpur (26.5°N, 80.3°E, 142 m amsl) during a winter season (December 2015 to February 2016). In addition, mass concentrations of organic and inorganic aerosol and BC were also measured. Diurnal variability in the absorption coefficient of BrC at 365 nm (babs_365) showed higher values (35 ± 21 Mm-1) during late evening to early morning hours and was attributed to primary emissions from biomass burning (BB) and fossil fuel burning (FFB). The babs_365 reduced by more than 80% as the day progressed, which was ascribed to photo bleaching/volatilization of BrC and/or due to rising boundary layer height. Further, diurnal variability in the ratios of babs_405/babs_365 and babs_420/babs_365 suggests that the BrC composition was not uniform throughout a day. WSOC exhibited a strong correlation with babs_365 (slope = 1.22 ± 0.007, r2 = 0.70, n = 13 265, intercept = -0.69 ± 0.17), suggesting the presence of a significant but variable fraction of chromophores. Mass absorption efficiency (MAE) values of WSOC ranged from 0.003 to 5.26 m2 g-1 (1.16 ± 0.60) during the study period. Moderate correlation (r2 = 0.50, slope = 1.58 ± 0.019, n = 6471) of babs_365 was observed with the semivolatile oxygenated organic aerosols (SV-OOA) fraction of BB resolved from positive matrix factorization (PMF) analysis of organic mass spectral data obtained from a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The low-volatility OOA (LV-OOA) fraction of BB had a similar correlation to babs_365 (r2 = 0.54, slope = 0.38 ± 0.004, n = 6471) but appears to have a smaller contribution to the absorption.
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Affiliation(s)
- Rangu Satish
- Geosciences Division, Physical Research Laboratory , Ahmedabad 380009, India
| | - Puthukkadan Shamjad
- Department of Civil Engineering and Centre for Environmental Science and Engineering, Indian Institute of Technology-Kanpur , Kanpur 208016, India
| | - Navaneeth Thamban
- Department of Civil Engineering and Centre for Environmental Science and Engineering, Indian Institute of Technology-Kanpur , Kanpur 208016, India
| | - Sachchida Tripathi
- Department of Civil Engineering and Centre for Environmental Science and Engineering, Indian Institute of Technology-Kanpur , Kanpur 208016, India
| | - Neeraj Rastogi
- Geosciences Division, Physical Research Laboratory , Ahmedabad 380009, India
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Shamjad PM, Tripathi SN, Thamban NM, Vreeland H. Refractive Index and Absorption Attribution of Highly Absorbing Brown Carbon Aerosols from an Urban Indian City-Kanpur. Sci Rep 2016; 6:37735. [PMID: 27883083 PMCID: PMC5121896 DOI: 10.1038/srep37735] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 10/31/2016] [Indexed: 11/09/2022] Open
Abstract
Atmospheric aerosols influence Earth's radiative balance, having both warming and cooling effects. Though many aerosols reflect radiation, carbonaceous aerosols such as black carbon and certain organic carbon species known as brown carbon have the potential to warm the atmosphere by absorbing light. Black carbon absorbs light over the entire solar spectrum whereas brown carbon absorbs near-UV wavelengths and, to a lesser extent, visible light. In developing countries, such as India, where combustion sources are prolific, the influence of brown carbon on absorption may be significant. In order to better characterize brown carbon, we present experimental and modeled absorption properties of submicron aerosols measured in an urban Indian city (Kanpur). Brown carbon here is found to be fivefold more absorbing at 365 nm wavelength compared to previous studies. Results suggest ~30% of total absorption in Kanpur is attributed to brown carbon, with primary organic aerosols contributing more than secondary organics. We report the spectral brown carbon refractive indices along with an experimentally constrained estimate of the influence of aerosol mixing state on absorption. We conclude that brown carbon in Kanpur is highly absorbing in nature and that the mixing state plays an important role in light absorption from volatile species.
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Affiliation(s)
- P. M. Shamjad
- Department of Civil Engineering, Indian Institute of Technology-Kanpur, Kanpur, India
| | - S. N. Tripathi
- Department of Civil Engineering, Indian Institute of Technology-Kanpur, Kanpur, India
- Centre for Environmental Science and Engineering, Indian Institute of Technology-Kanpur, Kanpur, India
| | - Navaneeth M. Thamban
- Department of Civil Engineering, Indian Institute of Technology-Kanpur, Kanpur, India
| | - Heidi Vreeland
- Department of Civil and Environmental Engineering, Duke University, North Carolina, USA
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