气候变化领域集成服务门户(CCPortal): Estimating contributions of black and brown carbon to solar absorption from aethalometer and AERONET measurements in the highly polluted Kathmandu Valley; Nepal

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DOI	10.1016/j.atmosres.2020.105164
	Estimating contributions of black and brown carbon to solar absorption from aethalometer and AERONET measurements in the highly polluted Kathmandu Valley; Nepal
	Kim S.-W.; Cho C.; Rupakheti M.
发表日期	2021
ISSN	0169-8095
卷号	247
英文摘要	We estimated the individual contributions of black carbon (BC) and brown carbon (BrC) to the aerosol absorption coefficient (σap) and absorption aerosol optical depth (AAOD) in the highly polluted Kathmandu Valley, Nepal, by applying the absorption Ångström exponent (AÅE) method to multi-wavelength aethalometer and AERONET sun/sky radiometer measurements. The elevated σap levels observed during the winter and pre-monsoon periods were primarily due to increased usage of diesel generators and low-grade fuel/coal. The AAODBC and AAODBrC values were substantially higher during the pre-monsoon period, almost two-fold higher than winter levels, due to seasonally increased biomass-burning activities from agricultural residue burning and forest fires. The overall contribution of BC to σap was approximately 80%–95%, whereas BrC accounted for 5%–20% at 520 nm. However, the BrC contribution to σap at 370 nm was substantially higher during the winter, ranging from 29.3% to 34.0%. The portioning of AERONET measurements indicates that BC contributed 80% (69%) while BrC contributed 20% (31%) to AAOD of carbonaceous aerosols at 520 nm (370 nm). Although the observation principles and techniques are completely independent, the BC and BrC absorption for simultaneous daytime data points shows a strong correlation between surface aethalometer-based and column AERONET-based estimates. The contributions of BC and BrC to absorption in Kathmandu Valley are similar to those observed under open biomass and garbage-burning conditions; however, the BrC absorption at both 370 and 520 nm is approximately 2- to 3-fold higher than those observed for urban areas in East Asia. © 2020 Elsevier B.V.
英文关键词	Absorption aerosol optical depth; Aerosol absorption coefficient; Black carbon; Brown carbon; Kathmandu
语种	英语
scopus关键词	Aerosols; Agricultural robots; Agricultural wastes; Atmospheric thermodynamics; Carbon; Deforestation; Landforms; Aerosol absorption; Aerosol optical depths; Carbonaceous aerosol; Diesel generators; Multi-wavelengths; Solar absorption; Strong correlation; Sun/sky radiometers; Bromine compounds; absorption; AERONET; aerosol; atmospheric pollution; biomass burning; black carbon; brown carbon; climate forcing; correlation; optical depth; Kathmandu Valley; Nepal
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/141762
作者单位	Seoul National University, School of Earth and Environmental Sciences, Seoul, South Korea; Institute for Advanced Sustainability Studies (IASS), Potsdam, Germany
推荐引用方式 GB/T 7714	Kim S.-W.,Cho C.,Rupakheti M.. Estimating contributions of black and brown carbon to solar absorption from aethalometer and AERONET measurements in the highly polluted Kathmandu Valley; Nepal[J],2021,247.
APA	Kim S.-W.,Cho C.,&Rupakheti M..(2021).Estimating contributions of black and brown carbon to solar absorption from aethalometer and AERONET measurements in the highly polluted Kathmandu Valley; Nepal.Atmospheric Research,247.
MLA	Kim S.-W.,et al."Estimating contributions of black and brown carbon to solar absorption from aethalometer and AERONET measurements in the highly polluted Kathmandu Valley; Nepal".Atmospheric Research 247(2021).