Abstract
The role of atmospheric aerosols in earth’s radiative balance is crucial. A thorough knowledge about the spectral optical properties of various types of aerosols is necessary to quantify the net radiative forcing produced by aerosol–light interactions. In this study, we exploited an open-source inverse algorithm based on the Python—PyMieScatt survey iteration method, to retrieve the wavelength dependent Mie-equivalent complex refractive indices of ambient aerosols. This method was verified by obtaining the broadband complex refractive indices of monodisperse polystyrene latex spheres and polydisperse common salt aerosols, using laboratory data collected with a supercontinuum broadband cavity enhanced extinction spectrometer operating in the 420–540 nm wavelength range. Field measurements of ambient aerosol were conducted using a similar cavity enhanced extinction spectrometer (IBBCEES) operating in the wavelength range of 400–550 nm, a multi-wavelength aethalometer, and a scanning mobility particle sizer, in Changzhou city, People’s Republic of China. The absorption coefficients for the entire wavelength range were retrieved using the absorption Ångström exponents calculated from a pair of measured absorption coefficients at known wavelengths. The survey iteration method takes scattering and absorption coefficients, wavelength, and size distributions as inputs; and it calculates the Mie-equivalent wavelength dependent complex refractive index (RI = n ± ik) and estimated errors. The retrieved field RI values ranged from 1.66 ≤ n ≤ 1.80 to 1.65 ≤ n ≤ 1.86 and from 0.036 ≤ k ≤ 0.038 to 0.062 ≤ k ≤ 0.067 in the wavelength range (400–550 nm), for low and high aerosol loading conditions, respectively. Additionally, we derived the spectral dependencies of scattering and absorption coefficients along with the n and k Ångström exponents (AE). The nAE and kAE estimated values suggest a stronger wavelength dependence for aerosol light scattering compared to absorption, and a decreasing trend for the spectrally dependent single scattering albedo during both loading conditions. The extremum of errors in the retrieved n and k values were quantified by considering (a) uncertainties in input parameters in the broad spectral region (400–550 nm), (b) using CAPS extinction values at 530 nm and (c) an estimated size distribution incorporating the coarse particles (at 530 nm).
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References
Abo Riziq A, Erlick C, Dinar E, Rudich Y, Riziq AA, Erlick C, Dinar E, Rudich Y (2006) Optical properties of absorbing and non-absorbing aerosols retrieved by cavity ring down (CRD) spectroscopy. Atmos Chem Phys Discuss 6(6):12347–12387
Andreae MO, Gelencsér A (2006) Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols. Atmos Chem Phys 6(10):3131–3148
Ångström A (1930) On the atmospheric transmission of sun radiation. II. Geogr Ann 12(2–3):130–159
Bergstrom RW, Russell PB, Hignett P (2002) Wavelength dependence of the absorption of black carbon particles: predictions and results from the TARFOX experiment and implications for the aerosol single scattering albedo. J Atmos Sci 59(3 PT 1):567–577
Bernardoni V, Ferrero L, Bolzacchini E, Forello AC, Gregorič A, Massabò D, Močnik G, Prati P, Rigler M, Santagostini L, Soldan F, Valentini S, Valli G, Vecchi R (2020) Determination of Aethalometer multiple-scattering enhancement parameters and impact on source apportionment during the winter 2017–2018 EMEP/ACTRIS/COLOSSAL campaign in Milan. Atmos Measure Tech Discuss 233:1–35
Bluvshtein N, Flores JM, Riziq AA, Rudich Y (2012) An approach for faster retrieval of aerosols’ complex refractive index using cavity ring-down spectroscopy. Aerosol Sci Technol 46(10):1140–1150. https://doi.org/10.1080/02786826.2012.700141
Bluvshtein N, Flores JM, Segev L, Rudich Y (2016) A new approach for retrieving the UV–vis optical properties of ambient aerosols. Atmos Measure Tech 9:3477–3490. https://doi.org/10.5194/amt-9-3477-2016
Bluvshtein N, Lin P, Michel Flores J, Segev L, Mazar Y, Tas E, Snider G, Weagle C, Brown SS, Laskin A, Rudich Y (2017) Broadband optical properties of biomass-burning aerosol and identification of brown carbon chromophores. J Geophys Res 122(10):5441–5456
Bohren C, Huffman D (1998) Absorption and scattering of light by small particles. Wiley, ISBN: 978-0-471-29340-8
Bond TC, Bergstrom RW (2007) Light absorption by carbonaceous particles: an investigative review. Aerosol Sci Technol 40(1):27–57. https://doi.org/10.1080/02786820500421521
Bond TC, Doherty SJ, Fahey DW, Forster PM, Berntsen T, Deangelo BJ, Flanner MG, Ghan S, Kärcher B, Koch D, Kinne S, Kondo Y, Quinn PK, Sarofim MC, Schultz MG, Schulz M, Venkataraman C, Zhang H, Zhang S, Bellouin N, Guttikunda SK, Hopke PK, Jacobson MZ, Kaiser JW, Klimont Z, Lohmann U, Schwarz JP, Shindell D, Storelvmo T, Warren SG, Zender CS (2013) Bounding the role of black carbon in the climate system: a scientific assessment. J Geophys Res Atmos 118(11):5380–5552
Browne EC, Zhang X, Franklin JP, Ridley KJ, Kirchstetter TW, Wilson KR, Cappa CD, Kroll JH (2019) Effect of heterogeneous oxidative aging on light absorption by biomass burning organic aerosol. Aerosol Sci Technol 53(6):663–674
Chamaillard KÃ, Kleefeld C, Jennings SG, Ceburnis D, Dowd CDO (2006) Light scattering properties of sea-salt aerosol particles inferred from modeling studies and ground-based measurements. J Quant Spectrosc Radiat Transfer 101:498–511
Cotterell MI, Szpek K, Haywood JM, Langridge JM (2020) Sensitivity and accuracy of refractive index retrievals from measured extinction and absorption cross sections for mobility-selected internally mixed light absorbing aerosols. Aerosol Sci Technol 54(9):1034–1057
Dubovik O, Holben BN, Kaufman YJ, Yamasoe M, Smimov A, Tanré D, Slutsker I (1998) Single-scattering albedo of smoke retrieved from the sky radiance and solar transmittance measured from ground. J Geophys Res Atmos 103(D24):31903–31923
Eck TF, Holben BN, Slutsker I, Setzer A (1998) Measurements of irradiance attenuation and estimation of aerosol single scattering albedo for biomass burning aerosols in Amazonia. J Geophys Res Atmos 103(D24):31865–31878
Flores JM, Trainic M, Borrmann S, Rudich Y (2009) Effective broadband refractive index retrieval by a white light optical particle counter. Phys Chem Chem Phys 11:7943–7950
Garg S, Chandra BP, Sinha V, Sarda-Esteve R, Gros V, Sinha B (2016) Limitation of the use of the absorption Ångström exponent for source apportionment of equivalent black carbon: a case study from the North West Indo-Gangetic Plain. Environ Sci Technol 50(2):814–824
Hansen J, Sato M, Ruedy R, Nazarenko L, Lacis A, Schmidt GA, Russell G, Aleinov I, Bauer M, Bauer S, Bell N, Cairns B, Canuto V, Chandler M, Cheng Y, Del Genio A, Faluvegi G, Fleming E, Friend A, Hall T, Jackman C, Kelley M, Kiang N, Koch D, Lean J, Lerner J, Lo K, Menon S, Miller R, Minnis P, Novakov T, Oinas V, Perlwitz Ja, Perlwitz Ju, Rind D, Romanou A, Shindell D, Stone P, Sun S, Tausnev N, Thresher D, Wielicki B, Wong T, Yao M, Zhang S (2005) Efficacy of climate forcings. J Geophys Res D: Atmos 110(18):1–45
Hobbs PV, Reid JS, Kotchenruther RA, Ferek RJ, Weiss R (1997) Direct radiative forcing by smoke from biomass burning. Science 275(5307):1776–1778
Jacobson MZ (2001) Strong radiative heating due to the mixing state of black carbon in atmospheric aerosols. Nature 409(6821):695–697
John S, Chen J, Zhang J, Pakkatil A, Wang M, Ramachandran A, Saseendran A, Thomas AP, Viswanathan D, Varma R (2021) A broadband cavity-enhanced spectrometer for atmospheric aerosol light extinction measurements. Aerosol Sci Technol. https://doi.org/10.1080/02786826.2021.1944604
Jordan CE, Anderson BE, Beyersdorf AJ, Corr CA, Dibb JE, Greenslade ME, Martin RF (2015) Spectral aerosol extinction ( SpEx ): a new instrument for in situ ambient aerosol extinction measurements across the UV/visible wavelength range. Atmos Measure Tech 8:4755–4771
Kandler K, Benker N, Bundke U, Cuevas E, Ebert M, Knippertz P, Rodrı S (2007) Chemical composition and complex refractive index of Saharan Mineral Dust at Izana, Tenerife (Spain) derived by electron microscopy. Atmos Environ 41:8058–8074
Kannosto J, Virtanen A, Lemmetty M, Mäkelä JM, Keskinen J, Junninen H, Hussein T, Aalto P, Kulmala M (2008) Mode resolved density of atmospheric aerosol particles. Atmos Chem Phys 8(17):5327–5337. https://doi.org/10.5194/acp-8-5327-2008
Keller-Rudek H, Moortgat GK, Sander R, Sörensen R (2013) The MPI-Mainz UV/VIS spectral atlas of gaseous molecules of atmospheric interest. Earth Syst Sci Data 5(2):365–373
Kiehl JT, Schneider TL, Rasch PJ, Barth MC, Wong J (2000) Radiative forcing due to sulfate aerosols from simulations with the National Center for Atmospheric Research Community Climate Model, Version 3. J Geophys Res 105:1441–1457
Kim J, Bauer H, Dobovičnik T, Hitzenberger R, Lottin D, Ferry D, Kim J, Bauer H, Dobovi T, Hitzenberger R, Lottin D, Ferry D, Petzold A (2015) Assessing optical properties and refractive index of combustion aerosol particles through combined experimental and modeling studies. Aerosol Sci Technol 49(340–350):2015
Kirchstetter TW, Novakov T, Hobbs PV (2004) Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon. J Geophys Res Atmos 109(21):1–12
Lack DA, Langridge JM (2013) On the attribution of black and brown carbon light absorption using the Ångström exponent. Atmos Chem Phys 13(20):10535–10543
Mack LA, Levin EJT, Kreidenweis SM, Obrist D, Moosmüller H, Lewis KA, Arnott WP, McMeeking GR, Sullivan AP, Wold CE, Hao WM, Collett JL, Malm WC (2010) Optical closure experiments for biomass smoke aerosols. Atmos Chem Phys 10(18):9017–9026
Manual, Condensation Particle Counter Model 3750., TSI Inc. 500 Cardigan Road Shoreview, Minnesota, 55126, USA
Manual, Electrostatic Classifier Model 3080., TSI Inc. 500 Cardigan Road Shoreview, Minnesota, 55126, USA
Moise T, Flores JM, Rudich Y (2015) Optical properties of secondary organic aerosols and their changes by chemical processes. Chem Rev 115(10):4400–4439
Moosmüller H, Chakrabarty RK, Arnott WP (2009) Aerosol light absorption and its measurement: a review. J Quant Spectrosc Radiat Transfer 110(11):844–878
Moosmüller H, Chakrabarty RK, Ehlers KM, Arnott WP (2011) Absorption Ångström coefficient, brown carbon, and aerosols: basic concepts, bulk matter, and spherical particles. Atmos Chem Phys 11(3):1217–1225
Müller T, Schladitz A, Massling A, Kaaden N, Kandler K, Wiedensohler A (2009) Spectral absorption coefficients and imaginary parts of refractive indices of Saharan dust during SAMUM-1. Tellus B Chem Phys Meteorol 61(1):79–95
Petzold A, Onasch T, Kebabian P, Freedman A (2013) Intercomparison of a cavity attenuated phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor. Atmos Meas Tech 6(5):1141–1151
Querry M (1987) Optical constants of minerals and other materials from the millimeter to the ultraviolet. 333
Radney JG, Zangmeister CD (2018) Comparing aerosol refractive indices retrieved from full distribution and size- and mass-selected measurements. J Quant Spectrosc Radiat Transfer. https://doi.org/10.1016/j.jqsrt.2018.08.021
Ramanathan V, Crutzen PJ, Kiehl JT, Rosenfeld D (2001) Atmosphere: aerosols, climate, and the hydrological cycle. Science 294(5549):2119–2124
Raut JC, Chazette P (2008) Radiative budget in the presence of multi-layered aerosol structures in the framework of AMMA SOP-0. Atmos Chem Phys 8(22):6839–6864
Russell PB, Bergstrom RW, Shinozuka Y, Clarke AD, Decarlo PF, Jimenez JL, Livingston JM, Redemann J, Dubovik O, Strawa A (2010) Absorption Ångström exponent in AERONET and related data as an indicator of aerosol composition. Atmos Chem Phys 10(3):1155–1169
Sarpong E, Smith D, Pokhrel R, Fiddler MN, Bililign S (2020) Refractive indices of biomass burning aerosols obtained from african biomass fuels using RDG approximation. Atmosphere 11(1):62
Saseendran A, Mathai S, Joshi S, Pakkattil A, Kinney G, Mazzoleni C, Varma R (2020) Dual-cavity spectrometer for monitoring broadband light extinction by atmospheric aerosols. Aerosol Sci Technol 54(10):1183–1196
Schkolnik G, Chand D, Hoffer A, Andreae MO, Erlick C (2007) Constraining the density and complex refractive index of elemental and organic carbon in biomass burning aerosol using optical and chemical measurements. Atmos Environ 41:1107–1118
Seinfeld JH, Pandis SN (1998) Atmospheric chemistry and physics from air pollution to climate change. Wiley, NewYork, pp 1–1309
Sharma N, Arnold IJ, Moosmüller H, Arnott WP, Mazzoleni C (2013) Photoacoustic and nephelometric spectroscopy of aerosol optical properties with a supercontinuum light source. Atmos Meas Techniques 6:3501–3513
Sokolik IN, Toon OB (1999) Incorporation of mineralogical composition into models of the radiative properties of mineral aerosol from UV to IR wavelengths. J Geophys Res 104:9423–9444
Sokolik IN, Toon OB, Bergstrom RW (1998) Modeling the rediative characteristics of airborne mineral aerosols at infrared wavelengths. J Geophys Res Atmos 103(D8):8813–8826
Spindler C, Riziq AA, Rudich Y (2007) Retrieval of aerosol complex refractive index by combining cavity ring down aerosol spectrometer measurements with full size distribution information. Aerosol Sci Technol 41(11):1011–1017
Stier P, Seinfeld JH, Kinne S, Boucher O (2007) Aerosol absorption and radiative forcing. Atmos Chem Phys 7:5237–5261. https://doi.org/10.5194/acp-7-5237-2007
Sultanova N, Kasarova S, Nikolov I (2009) Dispersion properties of optical polymers. Acta Phys Pol, A 116(4):585–587
Sumlin BJ, Heinson YW, Chakrabarty RK (2018a) Retrieving the aerosol complex refractive index using PyMieScatt: a Mie computational package with visualization capabilities. J Quant Spectrosc Radiat Transfer 205:127–134
Sumlin BJ, Heinson YW, Shetty N, Pandey A, Pattison RS, Baker S, Min W, Chakrabarty RK (2018b) UV–Vis–IR spectral complex refractive indices and optical properties of brown carbon aerosol from biomass burning. J Quant Spectrosc Radiat Transfer 206:392–398
Toole JR, Renbaum-wolff L, Smith GD (2013) A calibration technique for improving refractive index retrieval from aerosol cavity ring-down spectroscopy. Aerosol Sci Technol 47(9):955–965. https://doi.org/10.1080/02786826.2013.805875
Toon OB, Pollack JB, Khare BN (1976) The optical constants of several atmospheric aerosol species: ammonium sulfate, aluminum oxide, and sodium chloride. J Geophys Res 81(33):5733–5748
Valenzuela A, Olmo FJ, Lyamani H, Antón M, Titos G, Cazorla A, Alados-Arboledas L (2015) Aerosol scattering and absorption Angström exponents as indicators of dust and dust-free days over Granada (Spain). Atmos Res 154:1–13
Washenfelder RA, Flores JM, Brock CA, Brown SS, Rudich Y (2013) Broadband measurements of aerosol extinction in the ultraviolet spectral region. Atmos Meas Tech 6:861–877
Won Kim K (2015) Optical properties of size-resolved aerosol chemistry and visibility variation observed in the urban site of Seoul, Korea. Aerosol Air Qual Res 15(1):271–283
Xu Z, Wen T, Li X, Wang J, Wang Y (2015) Characteristics of carbonaceous aerosols in Beijing based on two-year observation. Atmos Pollut Res 6(2):202–208
Yu F, Luo G, Ma X (2012) Regional and global modeling of aerosol optical properties with a size, composition, and mixing state resolved particle microphysics model. Atmos Chem Phys 12(13):5719–5736
Zhang RJ, Cao J, Lee S, Shen Z, Ho KF (2007) Carbonaceous aerosols in PM10 and pollution gases in winter in Beijing. J Environ Sci 19(5):564–571
Zhang X, Lin YH, Surratt JD, Zotter P, Prévôt ASH, Weber RJ (2011) Light-absorbing soluble organic aerosol in Los Angeles and Atlanta: a contrast in secondary organic aerosol. Geophys Res Lett 38(21):2–5
Zhang X, Li Z, Wang F, Song M, Zhou X, Ming J (2020a) Carbonaceous aerosols in PM1, PM2.5, and PM10 Size fractions over the Lanzhou City Northwest China. Atmosphere 11:1368. https://doi.org/10.3390/atmos11121368
Zhang X, Qiu J, Li X, Zhao J, Liu L (2020b) Complex refractive indices measurements of polymers in visible and near-infrared bands. Appl Opt 59:2337–2344
Zhao W, Dong M, Chen W, Gu X, Hu C, Gao X, Huang W, Zhang W (2013) Wavelength-resolved optical extinction measurements of aerosols using broad-band cavity-enhanced absorption spectroscopy over the spectral range of 445–480 nm. Anal Chem 85:2260–2268
Zhao W, Xu X, Dong M, Chen W, Gu X, Hu C, Huang Y, Gao X, Huang W, Zhang W (2014) Development of a cavity-enhanced aerosol albedometer. Atmos Meas Tech 7(8):2551–2566
Zhao W, Xu X, Fang B, Zhang Q, Qian X, Wang S, Liu P, Zhang W, Wang Z, Liu D, Huang Y, Venables DS, Chen W (2017) Development of an incoherent broad-band cavity-enhanced aerosol extinction spectrometer and its application to measurement of aerosol optical hygroscopicity. Appl Opt 56(11):E16–E22
Zhao G, Yu Y, Tian P, Li J, Guo S, Zhao C (2020) Evaluation and correction of the ambient particle spectral light absorption measured using a filter-based aethalometer. Aerosol Air Qual Res 20(8):1833–1841
Zhou H, He J, Zhao B, Zhang L, Fan Q, Lü C, Dudagula A, Liu T, Yuan Y (2016) The distribution of PM10 and PM2.5 carbonaceous aerosol in Baotou China. Atmos Res 179:102–113
Zhu CS, Cao JJ, Ho KF, Antony Chen LW, Huang RJ, Wang YC, Li H, Shen ZX, Chow JC, Watson JG, Su X, Wang Q, Xiao S (2015) The optical properties of urban aerosol in northern China: a case study at Xi’an. Atmos Res 160:59–67
Zhu CS, Cao JJ, Tsai CJ, Shen ZX, Liu SX, Huang RJ, Zhang N, ning, and Wang, P. (2016) The rural carbonaceous aerosols in coarse, fine, and ultrafine particles during haze pollution in northwestern China. Environ Sci Pollut Res 23(5):4569–4575
Acknowledgements
The authors thankfully acknowledge financial support from the Kerala State Council for Science, Technology and Environment, project code “003/SRSPS/2015/CSTE”. CM acknowledges the support from the Elizabeth and Richard Henes Center for Quantum Phenomena at Michigan Technological University, the U.S. Department of Energy grant# DE-SC0021168 and the U.S. National Science Foundation grant# ATM-1625598. J. Chen acknowledges support from NO. SKLLQG1703, State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, NO. FDLAP 13003, Opening Project of Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), P. R. China.
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Saseendran, A., John, S., Pakkattil, A. et al. Retrieval of Broadband Optical Properties from Ambient Aerosols Measurements Using Inverse Mie Calculations. Aerosol Sci Eng 6, 111–125 (2022). https://doi.org/10.1007/s41810-021-00128-z
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DOI: https://doi.org/10.1007/s41810-021-00128-z