Influence of relative humidity and aging on the optical properties of organic aerosols from burning African biomass fuels.

IF 2.8 4区 环境科学与生态学 Q2 ENGINEERING, CHEMICAL
Aerosol Science and Technology Pub Date : 2024-10-11 eCollection Date: 2025-01-01 DOI:10.1080/02786826.2024.2412652
Megan M McRee, Vaios Moschos, Marc N Fiddler, Dario Massabò, Jason D Surratt, Solomon Bililign
{"title":"Influence of relative humidity and aging on the optical properties of organic aerosols from burning African biomass fuels.","authors":"Megan M McRee, Vaios Moschos, Marc N Fiddler, Dario Massabò, Jason D Surratt, Solomon Bililign","doi":"10.1080/02786826.2024.2412652","DOIUrl":null,"url":null,"abstract":"<p><p>Biomass burning (BB) is a major source of atmospheric fine carbonaceous aerosols, which play a significant, yet uncertain, role in modulating the Earth's radiation balance. However, accurately representing their optical properties in climate models remains challenging due to factors such as particle size, mixing state, combustion type, chemical composition, aging processes, and relative humidity (RH). In our study, we investigated BB organic-rich aerosols generated from smoldering sub-Saharan African biomass fuels. Fuel samples were collected in Africa and aerosols generated in the laboratory. We quantified key optical parameters, including mass cross-sections for extinction (2.04 ± 0.32 - 15.5 ± 2.48 m<sup>2</sup>/g), absorption (0.04 ± 0.01-0.3 ± 0.1 m<sup>2</sup>/g), and scattering (1.9 ± 0.68-15.3 ± 5.5 m<sup>2</sup>/g). Wavelength-dependent properties were used to determine absorption and scattering Ångström exponents. The single scattering albedo of these aerosols ranged from 0.8 ± 0.03 to 1.0 ± 0.04 and we observed a wavelength-dependent behavior. Extinction emission factors were determined at a wavelength of 550 nm, with values ranging from 42 ± 5 to 293 ± 32 m<sup>2</sup>/kg. Notably, optical properties exhibited fuel-type dependence, with differences observed between hardwood samples and other fuels, such as grass and animal dung. Aging increased mass extinction and scattering cross-sections at 550 nm, while humidity had the opposite effect across all fuels. Nitrate radical oxidation, both in photo and dark aging conditions, also influenced these properties. The findings are expected to close the gap in our understanding of optical properties of BB aerosol emissions in one of the least studied regions of the world - Africa - providing information to climate and air quality models for the region.</p>","PeriodicalId":7474,"journal":{"name":"Aerosol Science and Technology","volume":"59 5","pages":"544-566"},"PeriodicalIF":2.8000,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934956/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Aerosol Science and Technology","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1080/02786826.2024.2412652","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0

Abstract

Biomass burning (BB) is a major source of atmospheric fine carbonaceous aerosols, which play a significant, yet uncertain, role in modulating the Earth's radiation balance. However, accurately representing their optical properties in climate models remains challenging due to factors such as particle size, mixing state, combustion type, chemical composition, aging processes, and relative humidity (RH). In our study, we investigated BB organic-rich aerosols generated from smoldering sub-Saharan African biomass fuels. Fuel samples were collected in Africa and aerosols generated in the laboratory. We quantified key optical parameters, including mass cross-sections for extinction (2.04 ± 0.32 - 15.5 ± 2.48 m2/g), absorption (0.04 ± 0.01-0.3 ± 0.1 m2/g), and scattering (1.9 ± 0.68-15.3 ± 5.5 m2/g). Wavelength-dependent properties were used to determine absorption and scattering Ångström exponents. The single scattering albedo of these aerosols ranged from 0.8 ± 0.03 to 1.0 ± 0.04 and we observed a wavelength-dependent behavior. Extinction emission factors were determined at a wavelength of 550 nm, with values ranging from 42 ± 5 to 293 ± 32 m2/kg. Notably, optical properties exhibited fuel-type dependence, with differences observed between hardwood samples and other fuels, such as grass and animal dung. Aging increased mass extinction and scattering cross-sections at 550 nm, while humidity had the opposite effect across all fuels. Nitrate radical oxidation, both in photo and dark aging conditions, also influenced these properties. The findings are expected to close the gap in our understanding of optical properties of BB aerosol emissions in one of the least studied regions of the world - Africa - providing information to climate and air quality models for the region.

求助全文
约1分钟内获得全文 求助全文
来源期刊
Aerosol Science and Technology
Aerosol Science and Technology 环境科学-工程:化工
CiteScore
8.40
自引率
7.70%
发文量
73
审稿时长
3 months
期刊介绍: Aerosol Science and Technology publishes theoretical, numerical and experimental investigations papers that advance knowledge of aerosols and facilitate its application. Articles on either basic or applied work are suitable. Examples of topics include instrumentation for the measurement of aerosol physical, optical, chemical and biological properties; aerosol dynamics and transport phenomena; numerical modeling; charging; nucleation; nanoparticles and nanotechnology; lung deposition and health effects; filtration; and aerosol generation. Consistent with the criteria given above, papers that deal with the atmosphere, climate change, indoor and workplace environments, homeland security, pharmaceutical aerosols, combustion sources, aerosol synthesis reactors, and contamination control in semiconductor manufacturing will be considered. AST normally does not consider papers that describe routine measurements or models for aerosol air quality assessment.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信