气候变化领域集成服务门户(CCPortal): Light absorption by brown carbon over the South-East Atlantic Ocean

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DOI	10.5194/acp-22-9199-2022
	Light absorption by brown carbon over the South-East Atlantic Ocean
	Zhang, Lu; Segal-Rozenhaimer, Michal; Che, Haochi; Dang, Caroline; Sedlacek, Arthur J., III; Lewis, Ernie R.; Dobracki, Amie; Wong, Jenny P. S.; Formenti, Paola; Howell, Steven G.; Nenes, Athanasios
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	9199
结束页码	9213
卷号	22 期号:14 页码:15
英文摘要	Biomass burning emissions often contain brown carbon (BrC), which represents a large family of light-absorbing organics that are chemically complex, thus making it difficult to estimate their absorption of incoming solar radiation, resulting in large uncertainties in the estimation of the global direct radiative effect of aerosols. Here we investigate the contribution of BrC to the total light absorption of biomass burning aerosols over the South-East Atlantic Ocean with different optical models, utilizing a suite of airborne measurements from the ORACLES 2018 campaign. An effective refractive index of black carbon (BC), m(eBC) = 1.95 + ik(eBC), that characterizes the absorptivity of all absorbing components at 660 nm wavelength was introduced to facilitate the attribution of absorption at shorter wavelengths, i.e. 470 nm. Most values of the imaginary part of the effective refractive index, k(eBC), were larger than those commonly used for BC from biomass burning emissions, suggesting contributions from absorbers besides BC at 660 nm. The TEM-EDX single-particle analysis further suggests that these long-wavelength absorbers might include iron oxides, as iron is found to be present only when large values of k(eBC) are derived. Using this effective BC refractive index, we find that the contribution of BrC to the total absorption at 470 nm (R-BrC,(470)) ranges from similar to 8 %-22 %, with the organic aerosol mass absorption coefficient (MAC(OA,470)) at this wavelength ranging from 0.30 +/- 0.27 to 0.68 +/- 0.08 m(2) g(-1). The core-shell model yielded much higher estimates of MAC(OA,470) and R(BrC,470)( )than homogeneous mixing models, underscoring the importance of model treatment. Absorption attribution using the Bruggeman mixing Mie model suggests a minor BrC contribution of 4 % at 530 nm, while its removal would triple the BrC contribution to the total absorption at 470 nm obtained using the AAE (absorption Angstrom exponent) attribution method. Thus, it is recommended that the application of any optical properties-based attribution method use absorption coefficients at the longest possible wavelength to minimize the influence of BrC and to account for potential contributions from other absorbing materials.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000826358600001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273015
作者单位	Tel Aviv University; National Aeronautics & Space Administration (NASA); NASA Ames Research Center; United States Department of Energy (DOE); Oak Ridge National Laboratory; United States Department of Energy (DOE); Brookhaven National Laboratory; University of Miami; Mount Allison University; Centre National de la Recherche Scientifique (CNRS); UDICE-French Research Universities; Universite Paris Cite; Universite Paris-Est-Creteil-Val-de-Marne (UPEC); University of Hawaii System; University of Hawaii Manoa; Swiss Federal Institutes of Technology Domain; Ecole Polytechnique Federale de Lausanne; Foundation for Research & Technology - Hellas (FORTH)
推荐引用方式 GB/T 7714	Zhang, Lu,Segal-Rozenhaimer, Michal,Che, Haochi,et al. Light absorption by brown carbon over the South-East Atlantic Ocean[J],2022,22(14):15.
APA	Zhang, Lu.,Segal-Rozenhaimer, Michal.,Che, Haochi.,Dang, Caroline.,Sedlacek, Arthur J., III.,...&Nenes, Athanasios.(2022).Light absorption by brown carbon over the South-East Atlantic Ocean.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(14),15.
MLA	Zhang, Lu,et al."Light absorption by brown carbon over the South-East Atlantic Ocean".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.14(2022):15.