[1] Bond T C, Doherty S J, Fahey D W, et al. Bounding the role of black carbon in the climate system: A scientific assessment [J]. Journal of Geophysical Research: Atmospheres, 2013, 118(11): 5380-5552.
[2] Laskin A, Laskin J, Nizkorodov S A. Chemistry of atmospheric brown carbon [J]. Chemical Reviews, 2015, 115(10): 4335-4382.
[3] Andreae M O, Gelencsér A. Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols [J]. Atmospheric Chemistry and Physics, 2006, 6(10): 3131-3148.
[4] Bond T C, Bergstrom R W. Light absorption by carbonaceous particles: An investigative review [J]. Aerosol Science and Technology, 2006, 40(1): 27-67.
[5] Chung C E, Ramanathan V, Decremer D. Observationally constrained estimates of carbonaceous aerosol radiative forcing [J]. Proceedings of the National Academy of Sciences of the United States of America, 2012, 109(29): 11624-11629.
[6] Feng Y, Ramanathan V, Kotamarthi V R. Brown carbon: A significant atmospheric absorber of solar radiation? [J]. Atmospheric Chemistry and Physics, 2013, 13(17): 8607-8621.
[7] Jo D S, Park R J, Lee S, et al. A global simulation of brown carbon: Implications for photochemistry and direct radiative effect [J]. Atmospheric Chemistry and Physics, 2016, 16(5): 3413-3432.
[8] Huang R J, Yang L, Cao J J, et al. Brown carbon aerosol in urban Xi′an, Northwest China: The composition and light absorption properties [J]. Environmental Science & Technology, 2018, 52(12): 6825-6833.
[9] Wu C, Wang G H, Li J, et al. The characteristics of atmospheric brown carbon in Xi′an, inland China: Sources, size distributions and optical properties [J]. Atmospheric Chemistry and Physics, 2020, 20(4): 2017-2030.
[10] Liu J M, Lin P, Laskin A, et al. Optical properties and aging of light-absorbing secondary organic aerosol [J]. Atmospheric Chemistry and Physics, 2016, 16(19): 12815-12827.
[11] Monod A, Liu Y. Aerosol formation and heterogeneous chemistry in the atmosphere [J]. EPJ Web of Conferences, 2011, 18: 04002.
[12] Flores J M, Washenfelder R A, Adler G, et al. Complex refractive indices in the near-ultraviolet spectral region of biogenic secondary organic aerosol aged with ammonia [J]. Physical Chemistry Chemical Physics, 2014, 16(22): 10629-10642.
[13] Lin P, Laskin J, Nizkorodov S A, et al. Revealing brown carbon chromophores produced in reactions of methylglyoxal with ammonium sulfate [J]. Environmental Science & Technology, 2015, 49(24): 14257-14266.
[14] Chen L W A, Chow J C, Wang X L, et al. Multi-wavelength optical measurement to enhance thermal/optical analysis for carbonaceous aerosol [J]. Atmospheric Measurement Techniques, 2015, 8(1): 451-461.
[15] Chow J C, Watson J G, Green M C, et al. Separation of brown carbon from black carbon for IMPROVE and Chemical Speciation Network PM2.5 samples [J]. Journal of the Air & Waste Management Association, 2018, 68(5): 494-510.
[16] Zhao Z Z, Cao J J, Chow J C, et al. Multi-wavelength light absorption of black and brown carbon at a high-altitude site on the Southeastern margin of the Tibetan Plateau, China [J]. Atmospheric Environment, 2019, 212: 54-64.
[17] Peng C, Tian M, Wang X L, et al. Light absorption of brown carbon in PM2.5 in the Three Gorges Reservoir region, southwestern China: Implications of biomass burning and secondary formation [J]. Atmospheric Environment, 2020, 229: 117409.
[18] Li S, Zhu M, Yang W Q, et al. Filter-based measurement of light absorption by brown carbon in PM2.5 in a megacity in South China [J]. Science of the Total Environment, 2018, 633: 1360-1369.
[19] Kirillova E N, Andersson A, Han J, et al. Sources and light absorption of water-soluble organic carbon aerosols in the outflow from Northern China [J]. Atmospheric Chemistry and Physics, 2014, 14(3): 1413-1422.
[20] Chen D, Zhao Y, Lyu R T, et al. Seasonal and spatial variations of optical properties of light absorbing carbon and its influencing factors in a typical polluted city in Yangtze River Delta, China [J]. Atmospheric Environment, 2019, 199: 45-54.
[21] Qin Y M, Tan H B, Li Y J, et al. Chemical characteristics of brown carbon in atmospheric particles at a suburban site near Guangzhou, China [J]. Atmospheric Chemistry and Physics, 2018, 18(22): 16409-16418.
[22] Peng C, Yang F M, Tian M, et al. Brown carbon aerosol in two megacities in the Sichuan Basin of southwestern China: Light absorption properties and implications [J]. Science of the Total Environment, 2020, 719: 137483.
[23] Chen Y, Wenger J C, Yang F M, et al. Source characterization of urban particles from meat smoking activities in Chongqing, China using single particle aerosol mass spectrometry [J]. Environmental Pollution, 2017, 228: 92-101.
[24] Tian M, Liu Y, Yang F M, et al. Increasing importance of nitrate formation for heavy aerosol pollution in two megacities in Sichuan Basin, southwest China [J]. Environmental Pollution, 2019, 250: 898-905.
[25] Lack D A, Langridge J M. On the attribution of black and brown carbon light absorption using the ngstrm exponent [J]. Atmospheric Chemistry and Physics, 2013, 13(20): 10535-10543.
[26] Tian J, Wang Q Y, Ni H Y, et al. Emission characteristics of primary brown carbon absorption from biomass and coal burning: Development of an optical emission inventory for China [J]. Journal of Geophysical Research: Atmospheres, 2019, 124(3):1879-1893.
[27] Peng C, Tian M, Chen Y, et al. Characteristics, formation mechanisms and potential transport pathways of PM2.5 at a rural background site in Chongqing, southwest China [J]. Aerosol and Air Quality Research, 2019, 19(9): 1980-1992.
[28] Li H M, Wang Q G, Yang M, et al. Chemical characterization and source apportionment of PM2.5 aerosols in a megacity of Southeast China [J]. Atmospheric Research, 2016, 181: 288-299.
[29] Yudovich Y E, Ketris M P. Chlorine in coal: A review [J]. International Journal of Coal Geology, 2006, 67(1/2): 127-144.
[30] Tao J, Zhang L M, Zhang R J, et al. Uncertainty assessment of source attribution of PM2.5 and its water-soluble organic carbon content using different biomass burning tracers in positive matrix factorization analysis-a case study in Beijing, China [J]. Science of the Total Environment, 2016, 543: 326-335.
[31] Castro L M, Pio C A, Harrison R M, et al. Carbonaceous aerosol in urban and rural European atmospheres: Estimation of secondary organic carbon concentrations [J]. Atmospheric Environment, 1999, 33(17): 2771-2781.
[32] Cao J J, Wu F, Chow J C, et al. Characterization and source apportionment of atmospheric organic and elemental carbon during fall and winter of 2003 in Xi′an, China [J]. Atmospheric Chemistry and Physics, 2005, 5(11): 3127-3137.
[33] Zhang Q, Shen Z X, Lei Y L, et al. Variations of particle size distribution, black carbon, and brown carbon during a severe winter pollution event over Xi′an, China [J]. Aerosol and Air Quality Research, 2018, 18(6): 1419-1430.
[34] Zhu C S, Cao J J, Hu T F, et al. Spectral dependence of aerosol light absorption at an urban and a remote site over the Tibetan Plateau [J]. Science of the Total Environment, 2017, 590/591: 14-21.
[35] Yuan J F, Huang X F, Cao L M, et al. Light absorption of brown carbon aerosol in the PRD region of China [J]. Atmospheric Chemistry and Physics, 2016, 16(3): 1433-1443.
[36] Chen Y F, Ge X L, Chen H, et al. Seasonal light absorption properties of water-soluble brown carbon in atmospheric fine particles in Nanjing, China [J]. Atmospheric Environment, 2018, 187: 230-240.
[37] Wang J P, Nie W, Cheng Y F, et al. Light absorption of brown carbon in Eastern China based on 3-year multi-wavelength aerosol optical property observations and an improved absorption ngstrm exponent segregation method [J]. AtmosphericChemistry and Physics, 2018, 18(12): 9061-9074.
[38] Olson M R, Victoria G M, Robinson M A, et al. Investigation of black and brown carbon multiple-wavelength-dependent light absorption from biomass and fossil fuel combustion source emissions [J]. Journal of Geophysical Research: Atmospheres, 2015, 120(13): 6682-6697.
[39] Teich M, Van P D, Wang M, et al. Contributions of nitrated aromatic compounds to the light absorption of water-soluble and particulate brown carbon in different atmospheric environments in Germany and China [J]. Atmospheric Chemistry and Physics, 2017, 17(3): 1653-1672.
[40] Hecobian A, Zhang X, Zheng M, et al. Water-soluble organic aerosol material and the light-absorption characteristics of aqueous extracts measured over the Southeastern United States [J]. Atmospheric Chemistry and Physics, 2010, 10(13): 5965-5977.
[41] Peng C. Characteristics and Optical Properties of Brown Carbon in PM2.5 in Chongqing [D]. Chongqing: University of Chinese Academy of Sciences (Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences), 2020.
[42] Zeng Y L, Shen Z X, Takahama S, et al. Molecular absorption and evolution mechanisms of PM2.5 brown carbon revealed by electrospray ionization Fourier transform-ion cyclotron resonance mass spectrometry during a severe winter pollution episode in Xi′an, China [J]. Geophysical Research Letters, 2020, 47(10): e2020GL087977.
[43] Bones D L, Henricksen D K, Mang S A, et al. Appearance of strong absorbers and fluorophores in limonene-O3 secondary organic aerosol due to NH4+-mediated chemical aging over long time scales [J]. Journal of Geophysical Research: Atmospheres, 2010, 115(D5): D05203.
[44] Lu Z F, Streets D G, Winijkul E, et al. Light absorption properties and radiative effects of primary organic aerosol emissions [J]. Environmental Science & Technology, 2015, 49(8): 4868-4877.
[45] Saleh R, Robinson E S, Tkacik D S, et al. Brownness of organics in aerosols from biomass burning linked to their black carbon content [J]. Nature Geoscience, 2014, 7(9): 647-650.
[46] Saleh R, Hennigan C J, McMeeking G R, et al. Absorptivity of brown carbon in fresh and photo-chemically aged biomass-burning emissions [J]. Atmospheric Chemistry and Physics, 2013, 13(15): 7683-7693.
[47] Zeng Y L, Ning Y L, Shen Z X, et al. The roles of N, S, and O in molecular absorption features of brown carbon in PM2.5 in a typical semi-arid megacity in Northwestern China [J]. Journal of Geophysical Research: Atmospheres, 2021, 126(16): e2021JD034791.
[48] Levinson R, Akbari H, Berdahl P. Measuring solar reflectance-Part I: Defining a metric that accurately predicts solar heat gain [J]. Solar Energy, 2010, 84(9): 1717-1744.
[49] Hammer M S, Martin R V, Van D A, et al. Interpreting the ultraviolet aerosol index observed with the OMI satellite instrument to understand absorption by organic aerosols: Implications for atmospheric oxidation and direct radiative effects [J]. Atmospheric Chemistry and Physics, 2016, 16(4): 2507-2523.
