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Devaprasad M, Rastogi N, Satish R, Patel A, Dabhi A, Shivam A, Bhushan R, Meena R. Dual carbon isotope-based brown carbon aerosol characteristics at a high-altitude site in the northeastern Himalayas: Role of biomass burning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169451. [PMID: 38143007 DOI: 10.1016/j.scitotenv.2023.169451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 11/10/2023] [Accepted: 12/15/2023] [Indexed: 12/26/2023]
Abstract
PM2.5 samples (n = 34) were collected from January to April 2017 over Shillong (25.7°N, 91.9°E; 1064 m amsl), a high-altitude site situated in the northeastern Himalaya. The main aim was to understand the sources, characteristics, and optical properties of local vs long-range transported carbonaceous aerosols (CA) using chemical species and dual carbon isotopes (13C and 14C). Percentage biomass burning (BB)/biogenic fraction (fbio, calculated from 14C) varied from 67 to 92 % (78 ± 7) and correlated well with primary BB tracers like f60, and K+, suggesting BB as a considerable source. Rain events are shown to reduce the fbio fraction, indicating majority of BB-derived CA are transported. Further, δ13C (-26.6 ± 0.4) variability was very low over Shillong, suggesting it's limitations in source apportionment over the study region, if used alone. Average ratio of absorption coefficient of methanol-soluble BrC (BrCMS) to water-soluble BrC (BrCWS) at 365 nm was 1.8, indicating a significant part of BrC was water-insoluble. A good positive correlation between fbio and mass absorption efficiency of BrCWS and BrCMS at 365 nm with the higher slope for BrCMS suggests BB derived water-insoluble BrC was more absorbing. Relative radiative forcing (RRF, 300 to 2500 nm) of BrCWS and BrCMS with respect to EC were 11 ± 5 % and 23 ± 16 %, respectively. Further, the RRF of BrCMS was up to 60 %, and that of BrCWS was up to 22 % with respect to EC for the samples with fbio ≥ 0.85 (i.e., dominated by BB), reflecting the importance of BB in BrC RRF estimation.
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Affiliation(s)
- M Devaprasad
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India; Indian Institute of Technology, Gandhinagar, Gujarat 382355, India
| | - N Rastogi
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India.
| | - R Satish
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - A Patel
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - A Dabhi
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - A Shivam
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - R Bhushan
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
| | - R Meena
- Geosciences Division, Physical Research Laboratory, Ahmedabad 380009, India
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Paraskevopoulou D, Kaskaoutis DG, Grivas G, Bikkina S, Tsagkaraki M, Vrettou IM, Tavernaraki K, Papoutsidaki K, Stavroulas I, Liakakou E, Bougiatioti A, Oikonomou K, Gerasopoulos E, Mihalopoulos N. Brown carbon absorption and radiative effects under intense residential wood burning conditions in Southeastern Europe: New insights into the abundance and absorptivity of methanol-soluble organic aerosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 860:160434. [PMID: 36427708 DOI: 10.1016/j.scitotenv.2022.160434] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/04/2022] [Accepted: 11/19/2022] [Indexed: 06/16/2023]
Abstract
Biomass burning is a major source of Brown Carbon (BrC), strongly contributing to radiative forcing. In urban areas of the climate-sensitive Southeastern European region, where strong emissions from residential wood burning (RWB) are reported, radiative impacts of carbonaceous aerosols remain largely unknown. This study examines the absorption properties of water- and methanol-soluble organic carbon (WSOC, MeS_OC) in a city (Ioannina, Greece) heavily impacted by RWB. Measurements were performed during winter (December 2019 - February 2020) and summer (July - August 2019) periods, characterized by RWB and photochemical processing of organic aerosol (OA), respectively. PM2.5 filter extracts were analyzed spectrophotometrically for water- and methanol-soluble BrC (WS_BrC, MeS_BrC) absorption. WSOC concentrations were quantified using TOC analysis, while those of MeS_OC were determined using a newly developed direct quantification protocol, applied for the first time to an extended series of ambient samples. The direct method led to a mean MeS_OC/OC of 0.68 and a more accurate subsequent estimation of absorption efficiencies. The mean winter WS_BrC and MeS_BrC absorptions at 365 nm were 13.9 Mm-1 and 21.9 Mm-1, respectively, suggesting an important fraction of water-insoluble OA. Mean winter WS_BrC and MeS_BrC absorptions were over 10 times those observed in summer. MeS_OC was more absorptive than WSOC in winter (mean mass absorption efficiencies - MAE365: 1.81 vs 1.15 m2 gC-1) and especially in summer (MAE: 1.12 vs 0.27 m2 gC-1) due to photo-dissociation and volatilization of BrC chromophores. The winter radiative forcing (RF) of WS_BrC and MeS_BrC relative to elemental carbon (EC) was estimated at 8.7 % and 16.7 %, respectively, in the 300-2500 nm band. However, those values increased to 48.5 % and 60.2 % at 300-400 nm, indicating that, under intense RWB, BrC forcing becomes comparable to that of soot. The results highlight the consideration of urban BrC emissions in radiative transfer models, as a considerable climate forcing factor.
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Affiliation(s)
- D Paraskevopoulou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece.
| | - D G Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece.
| | - G Grivas
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - S Bikkina
- CSIR-National Institute of Oceanography, Dona Paula, Goa 403 004, India
| | - M Tsagkaraki
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
| | - I M Vrettou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - K Tavernaraki
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
| | - K Papoutsidaki
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
| | - I Stavroulas
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece; Climate and Atmosphere Research Center, The Cyprus Institute, 2121 Nicosia, Cyprus
| | - E Liakakou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - A Bougiatioti
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - K Oikonomou
- Climate and Atmosphere Research Center, The Cyprus Institute, 2121 Nicosia, Cyprus
| | - E Gerasopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece
| | - N Mihalopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, P. Penteli, Athens 15236, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 70013 Crete, Greece
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Sharma B, Jia S, Polana AJ, Ahmed MS, Haque RR, Singh S, Mao J, Sarkar S. Seasonal variations in aerosol acidity and its driving factors in the eastern Indo-Gangetic Plain: A quantitative analysis. CHEMOSPHERE 2022; 305:135490. [PMID: 35760126 DOI: 10.1016/j.chemosphere.2022.135490] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/30/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
This study employs ISORROPIA-II for the evaluation of aerosol acidity and quantification of contributions from chemical species and meteorological parameters to acidity variation in the Indian context. PM2.5 samples collected during summer (April-July 2018), post-monsoon (September-November 2018), and winter (December 2018-January 2019) from a rural receptor location in the eastern Indo-Gangetic Plain (IGP) were analyzed for ionic species, water-soluble organic carbon (WSOC), and organic and elemental carbon (OC, EC) fractions. This was followed by estimation of the in situ aerosol pH and liquid water content (LWC) using the forward mode of ISORROPIA-II, which is less sensitive to measurement uncertainty compared to the reverse mode, for a K+-Ca2+-Mg2+-NH4+-Na+-SO42--NO3--Cl--H2O system. Aerosol pH was moderately acidic (summer: 2.93 ± 0.67; post-monsoon: 2.67 ± 0.23; winter: 3.15 ± 0.34) and was most sensitive to SO42- and total ammonium (TNH3) variation. The LWC of aerosol showed an increasing trend from summer (16.6 ± 13.6 μg m-3) through winter (32.9 ± 10.4 μg m-3). With summer as the baseline, the largest changes in aerosol pH during the other seasons was driven by SO42- (ΔpH: -0.70 to -0.82 units), followed by TNH3 (ΔpH: +0.25 to +0.38 units) with K+ and temperature being significant only during winter (ΔpH: +0.51 and + 0.46 units, respectively). The prevalent acidity regime provided three major insights: i) positive summertime Cl- depletion (49 ± 20%) as a consequence of SO42- substitution increased aerosol pH by 0.03 ± 0.20 units and decreased LWC by 2.4 ± 5.9 μg m-3; ii) the rate of strong acidity (H+str) neutralization and the [H+str]/[SO42-] molar ratio suggested the existence of bounded acidity in ammonium-rich (winter) conditions; and iii) significant correlations between LWC, WSOC, and secondary organics during post-monsoon and winter pointed towards a possible indirect role of WSOC in enhancing LWC of aerosol, thereby increasing pH. Given the inability of proxies such as H+str and charge ratios to accurately represent aerosol pH as demonstrated here, this study emphasizes the need for rigorous thermodynamic model-based evaluation of aerosol acidity in the Indian scenario.
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Affiliation(s)
- Bijay Sharma
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India; School of Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh, 175075, India
| | - Shiguo Jia
- Guangdong Provincial Field Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, Guangzhou, 510275, PR China; School of Atmospheric Sciences, Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519082, PR China
| | - Anurag J Polana
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Md Sahbaz Ahmed
- Department of Environmental Science, Tezpur University, Tezpur, Assam, 784028, India
| | - Raza Rafiqul Haque
- Department of Environmental Science, Tezpur University, Tezpur, Assam, 784028, India
| | - Shruti Singh
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India
| | - Jingying Mao
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, 510632, PR China
| | - Sayantan Sarkar
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia, West Bengal, 741246, India; School of Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh, 175075, India.
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Afsana S, Zhou R, Miyazaki Y, Tachibana E, Deshmukh DK, Kawamura K, Mochida M. Abundance, chemical structure, and light absorption properties of humic-like substances (HULIS) and other organic fractions of forest aerosols in Hokkaido. Sci Rep 2022; 12:14379. [PMID: 35999376 PMCID: PMC9399238 DOI: 10.1038/s41598-022-18201-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/08/2022] [Indexed: 11/17/2022] Open
Abstract
Atmospheric organic aerosol (OA) are considered as a significant contributor to the light absorption of OA, but its relationship with abundance, composition and sources are not understood well. In this study, the abundance, chemical structural characteristics, and light absorption property of HULIS and other low-to-high polar organics in PM0.95 collected in Tomakomai Experimental Forest (TOEF) were investigated with consideration of their possible sources. HULIS were the most abundant (51%), and correlation analysis revealed that biogenic secondary organic aerosols significantly contribute to HULIS. The mass spectra obtained using a high-resolution aerosol mass spectrometer (HR-AMS) showed that HULIS and highly polar water-soluble organic matter (HP-WSOM) were substantially oxygenated organic aerosol fractions, whereas water-insoluble organic matter (WISOM) had a low O/C ratio and more hydrocarbon-like structures. The WISOM fraction was the predominant light-absorbing organics. HULIS and WISOM showed a noticeable seasonal change in mass absorption efficiency (MAE365), which was highest in winter. Further, HULIS were shown to be less absorbing than those reported for urban sites. The findings in this study provide insights into the contribution of biogenic secondary OA on aerosol property and radiative forcing under varying contributions from other types of OA.
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Affiliation(s)
- Sonia Afsana
- Graduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, Japan
| | - Ruichen Zhou
- Graduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, Japan
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, 464-8601, Japan
| | - Yuzo Miyazaki
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Eri Tachibana
- Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0819, Japan
| | - Dhananjay Kumar Deshmukh
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, 487-8501, Japan
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, 695022, India
| | - Kimitaka Kawamura
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, 487-8501, Japan
| | - Michihiro Mochida
- Graduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, Japan.
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, 464-8601, Japan.
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5
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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: 14] [Impact Index Per Article: 4.7] [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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Wen H, Zhou Y, Xu X, Wang T, Chen Q, Chen Q, Li W, Wang Z, Huang Z, Zhou T, Shi J, Bi J, Ji M, Wang X. Water-soluble brown carbon in atmospheric aerosols along the transport pathway of Asian dust: Optical properties, chemical compositions, and potential sources. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 789:147971. [PMID: 34082197 DOI: 10.1016/j.scitotenv.2021.147971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 06/12/2023]
Abstract
As an important type of light-absorbing aerosol, brown carbon (BrC) has the potential to affect the atmospheric photochemistry and Earth's energy budget. A comprehensive field campaign was carried out along the transport pathway of Asian dust during the spring of 2016, including a desert site (Erenhot), a rural site (Zhangbei), and an urban site (Jinan), in northern China. Optical properties, bulk chemical compositions, and potential sources of water-soluble brown carbon (WS-BrC) were investigated in atmospheric total suspended particulate (TSP) samples. Samples from Zhangbei had higher mass absorption efficiency at 365 nm (MAE365, 1.32 ± 0.34 m2 g-1) than those from Jinan (1.00 ± 0.23 m2 g-1) and Erenhot (0.84 ± 0.30 m2 g-1). Compere to the non-dust samples, elevated water-soluble organic carbon (WSOC) concentrations and MAE365 values of dust samples from Erenhot are related to the input of high molecular weight organic compounds and biogenic matter from the Gobi Desert, while lower values from Zhangbei and Jinan are attributed to the dilution effect caused by strong northwesterly winds. Based on fluorescence excitation-emission matrix spectra and parallel factor analysis, two humic-like (C1 and C2) and two protein-like (C3 and C4) substances were identified. Together, C1 and C2 accounted for ~64% of total fluorescence intensity at the highly polluted urban Jinan site; C3 represented ~45% at the rural Zhangbei site where local biomass burning affects; and C4 contributed ~24% in the desert region (Erenhot) due to dust-sourced biogenic substances. The relative absorptive forcing of WS-BrC compared to black carbon at 300-400 nm was about 31.3%, 13.9%, and 9.2% during non-dust periods at Erenhot, Zhangbei, and Jinan, respectively, highlighting that WS-BrC may significantly affect the radiative balance of Earth's climate system and should be included in radiative forcing models.
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Affiliation(s)
- Hui Wen
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China; Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Yue Zhou
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xuanye Xu
- College of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225, China
| | - Tianshuang Wang
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Quanliang Chen
- College of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu 610225, China
| | - Qingcai Chen
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Weijun Li
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 320007, China
| | - Zhe Wang
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Zhongwei Huang
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tian Zhou
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Jinsen Shi
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Jianrong Bi
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Mingxia Ji
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xin Wang
- Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China; Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China.
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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: 13] [Impact Index Per Article: 4.3] [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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Hettiyadura APS, Garcia V, Li C, West CP, Tomlin J, He Q, Rudich Y, Laskin A. Chemical Composition and Molecular-Specific Optical Properties of Atmospheric Brown Carbon Associated with Biomass Burning. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:2511-2521. [PMID: 33499599 DOI: 10.1021/acs.est.0c05883] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study provides molecular insights into the light absorption properties of biomass burning (BB) brown carbon (BrC) through the chemical characterization of tar condensates generated from heated wood pellets at oxidative and pyrolysis conditions. Both liquid tar condensates separated into "darker oily" and "lighter aqueous" immiscible phases. The molecular composition of these samples was investigated using reversed-phase liquid chromatography coupled with a photodiode array detector and a high-resolution mass spectrometer. The results revealed two sets of BrC chromophores: (1) common to all four samples and (2) specific to the "oily" fractions. The common BrC chromophores consist of polar, monoaromatic species. The oil-specific BrC chromophores include less-polar and nonpolar polyaromatic compounds. The most-light-absorbing pyrolysis oily phase (PO) was aerosolized and size-separated using a cascade impactor to compare the composition and optical properties of the bulk versus the aerosolized BrC. The mass absorption coefficient (MAC300-500 nm) of aerosolized PO increased compared to that of the bulk, due to gas-phase partitioning of more volatile and less absorbing chromophores. The optical properties of the aerosolized PO were consistent with previously reported ambient BB BrC measurements. These results suggest the darkening of atmospheric BrC following non-reactive evaporation that transforms the optical properties and composition of aged BrC aerosols.
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Affiliation(s)
| | | | - Chunlin Li
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | | | - Quanfu He
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yinon Rudich
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
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Satish R, Rastogi N, Singh A, Singh D. Change in characteristics of water-soluble and water-insoluble brown carbon aerosols during a large-scale biomass burning. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:33339-33350. [PMID: 32533475 DOI: 10.1007/s11356-020-09388-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Light-absorbing organic aerosol (brown carbon (BrC)) can significantly affect Earth's radiation budget and hydrological cycle. Biomass burning (BB) is among the major sources of atmospheric BrC. In this study, day/night pair (10-h integrated) of ambient PM2.5 were sampled every day before (defined as T1, n = 21), during (T2, n = 36), and after (T3, n = 8) a large-scale paddy-residue burning during October-November over Patiala (30.2° N, 76.3° E, 250 m amsl), a site located in the northwestern Indo-Gangetic Plain (IGP). PM2.5 concentration varied from ~ 90 to 500 μg m-3 (average ± 1σ standard deviation 230 ± 114) with the average values of 154 ± 57, 271 ± 122, and 156 ± 18 μg m-3 during T1, T2, and T3 periods, respectively, indicating the influence of BB emissions on ambient air quality. The absorption coefficient of BrC (babs) is calculated from the high-resolution absorption spectra of water-soluble and methanol-soluble organic carbon measured at 300 to 700 nm, and that at 365 nm (babs_365) is used as a general measure of BrC. The babs_365_Water and babs_365_Methanol ranged ~ 2 to 112 Mm-1 (avg 37 ± 27) and ~ 3 to 457 Mm-1 (avg 121 ± 108), respectively, suggesting a considerable presence of water-insoluble BrC. Contrasting differences were also observed in the daytime and nighttime values of babs_365_Water and babs_365_Methanol. Further, the levoglucosan showed a strong correlation with K+ (slope = 0.89 ± 0.06, R = 0.92) during the T2 period. We propose that this slope (~ 0.9) can be used as a typical characteristics of the emissions from paddy-residue burning over the IGP. Absorption Ångström exponent (AAE) showed a clear day/night variability during the T2 period, and lower AAEMethanol compared to AAEWater throughout the sampling period. Further at 365 nm, average relative atmospheric radiative forcing (RRF) for BrCWater is estimated to be ~ 17%, whereas that of BrCMethanol ~ 62% with respect to elemental carbon, suggesting that BrC radiative forcing could be largely underestimated by studies those use BrCWater only as a surrogate of total BrC.
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Affiliation(s)
- Rangu Satish
- Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad, 380009, India
- Stockholm University, 11419, Stockholm, Sweden
| | - Neeraj Rastogi
- Geosciences Division, Physical Research Laboratory, Navrangpura, Ahmedabad, 380009, India.
| | - Atinderpal Singh
- Department of Physics, Punjabi University, Patiala, 147002, India
- National Central University, Taoyuan, 32001, Taiwan
| | - Darshan Singh
- Department of Physics, Punjabi University, Patiala, 147002, India
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Zhang Q, Shen Z, Zhang L, Zeng Y, Ning Z, Zhang T, Lei Y, Wang Q, Li G, Sun J, Westerdahl D, Xu H, Cao J. Investigation of Primary and Secondary Particulate Brown Carbon in Two Chinese Cities of Xi'an and Hong Kong in Wintertime. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:3803-3813. [PMID: 32150391 DOI: 10.1021/acs.est.9b05332] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Brown carbon (BrC), an aerosol carbonaceous matter component, impacts atmospheric radiation and global climate because of its absorption in the near-ultraviolet-visible region. Simultaneous air sampling was conducted in two megacities of Xi'an (northern) and Hong Kong (southern) in China in winter of 2016-2017. The aim of this study is to determine and characterize the BrC compounds in collected filter samples. Characteristic absorption peaks corresponding to aromatic C-C stretching bands, organo-nitrates, and C═O functional groups were seen in spectra of Xi'an samples, suggesting that the BrC was derived from freshly smoldering biomass and coal combustion as well as aqueous formation of anthropogenic secondary organic carbon. In Hong Kong, the light absorption of secondary BrC accounted for 76% of the total absorbances of BrC. The high abundance of strong C═O groups, biogenic volatile organic compounds (BVOCs) and atmospheric oxidants suggest secondary BrC was likely formed from photochemical oxidation of BVOCs in Hong Kong. Several representative BrC molecular markers were detected using Fourier transform ion cyclotron resonance mass spectrometry and their absorption properties were simulated by quantum chemistry. The results demonstrate that light absorption capacities of secondary anthropogenic BrC with nitro-functional groups were stronger than those of biogenic secondary BrC and anthropogenic primary BrC.
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Affiliation(s)
- Qian Zhang
- Key Laboratory of Northwest Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhenxing Shen
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
- Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Leiming Zhang
- Air Quality Research Division, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Canada
| | - Yaling Zeng
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhi Ning
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Tian Zhang
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yali Lei
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qiyuan Wang
- Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Guohui Li
- Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Jian Sun
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Dane Westerdahl
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Hongmei Xu
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Junji Cao
- Key Lab of Aerosol Chemistry & Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
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Liakakou E, Kaskaoutis DG, Grivas G, Stavroulas I, Tsagkaraki M, Paraskevopoulou D, Bougiatioti A, Dumka UC, Gerasopoulos E, Mihalopoulos N. Long-term brown carbon spectral characteristics in a Mediterranean city (Athens). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 708:135019. [PMID: 31791764 DOI: 10.1016/j.scitotenv.2019.135019] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/02/2019] [Accepted: 10/15/2019] [Indexed: 05/19/2023]
Abstract
This study analyses 4-years of continuous 7-λ Aethalometer (AE-33) measurements in an urban-background environment of Athens, to resolve the spectral absorption coefficients (babs) for black carbon (BC) and brown carbon (BrC). An important BrC contribution (23.7 ± 11.6%) to the total babs at 370 nm is estimated for the period May 2015-April 2019, characterized by a remarkable seasonality with winter maximum (33.5 ± 13.6%) and summer minimum (18.5 ± 8.1%), while at longer wavelengths the BrC contribution is significantly reduced (6.8 ± 3.6% at 660 nm). The wavelength dependence of the total babs gives an annual-mean AAE370-880 of 1.31, with higher values in winter night-time. The BrC absorption and its contribution to babs presents a large increase reaching up to 39.1 ± 13.6% during winter nights (370 nm), suggesting residential wood burning (RWB) emissions as a dominant source for BrC. This is supported by strong correlations of the BrC absorption with OC, EC, the fragment ion m/z 60 derived from ACSM and PMF-analyzed organic fractions related to biomass burning (e.g. BBOA). In contrast, BrC absorption decreases significantly during daytime as well as in the warm period, reaching to a minimum during the early-afternoon hours in all seasons due to photo-chemical degradation. Estimated secondary BrC absorption is practically evident only during winter night-time, implying the fast oxidation of BrC species from RWB emissions. Changes in mixing-layer height do not significantly affect the BrC absorption in winter, while they play a major role in summer.
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Affiliation(s)
- E Liakakou
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece.
| | - D G Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece
| | - 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
| | - M Tsagkaraki
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece
| | - D Paraskevopoulou
- 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
| | - U C Dumka
- Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 001, India
| | - 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; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece.
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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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