Art Sedlacek
Chemist, Aerosol Processes & Observing Systems, Environmental and Climate Sciences Department

Brookhaven National Laboratory
Environmental and Climate Sciences Department
Bldg. 815, Room 1-46
P.O. Box 5000
Upton, NY 11973-5000
(631) 344-2404
sedlacek@bnl.gov
Dr. Arthur J. Sedlacek is an atmospheric chemist within the Environmental & Climate Sciences Department where he also serves at technical manager for the Aerosol Direct Effects group. He received his Ph.D. in physical chemistry from the University of Utah where his thesis research focused on the use of infrared and Raman spectroscopies to follow reaction dynamics in both amorphous solids and in the gas phase. His post-doctoral research centered on understanding the complex energy transfer mechanisms and reaction dynamics associated with highly-vibrationally excited molecules. After joining the BNL scientific staff in 1992, he helped establish the first-ever remote sensing program at BNL and in 1999, Dr. Sedlacek's group designed the first ever Raman lidar system specifically for the short-range, in situ, non-contact detection and identification of ground contamination. This groundbreaking work, developed to support civilian First Responders and Haz/Mat professionals, was awarded a patent in 2003.
Since joining the Environmental & Climate Sciences Department in 2004, Dr. Sedlacek's research has focused on elucidating the contribution black carbon has to aerosol direct radiative forcing. This work resulted in the development of a new instrument, based on photothermal interferometry, for the in situ measurement of black carbon. More recently, he has expanded his research interests to examine how atmospheric aging affects both the optical and microphysica properties of black carbon. Dr. Sedlacek has organized several symposia on the application of lidar and vibrational spectroscopy for chemical and biological sensing. He has presented the results of his research at numerous national and international forums, through invited talks and in peer-reviewed publications.
Expertise | Research | Education | Appointments | Publications | Awards
Expertise
- Understanding the atmospheric aging on the optical and microphysical properties of soot and related aerosols
- Development of model aerosol systems to elucidate the effects of encapsulation on aerosol optical properties
- Aerosol radiative forcing and how it relates to global climate change
- Development of novel optical-based instrumentation for aerosol, chemical and biological species detection
- Measurement of fundamental spectroscopic properties
Research Activities
- Research Chemist, Brookhaven National Laboratory; Jan 1992 - present
- Postdoctoral Research Associate, Brookhaven National Laboratory; Jan 1989-Sept 1992
Education
- University of Utah, Ph.D., Chemical Dynamics
Dissertation topic: "Photochemistry of Amorphous Solids" - University of Wyoming, Laramie, B.S., Chemistry
Professional Appointments
- American Chemical Society (ACS)
- Optical Society of America, (OSA)
- American Geophysical Union (AGU)
- American Association for Aerosol Research (AAAR)
- Session chairs for AGU and AAAR conferences
- Organized symposia on the application of optical sensors for Homeland Security for the International Society for Optical Engineering (1996, 1997, 1999, 2001, 2001, 2002, 2003, 2004, 2005) as well as serving on the Executive Program committee (2001, 2003, and 2004)
- Guest Editor: IEEE Sensors Journal; Special Issue on Sensors for the Prevention of Terrorists Acts (2004)
- Participation in Department of Energy/National Security and Nonproliferation Congressional Hill EXPO (1998 and 1999)
Selected Publications
- Che H, Segal-Rozenhaimer M, Zhang L, et al (2022) Cloud processing and weeklong ageing affect biomass burning aerosol properties over the south-eastern Atlantic. Communications Earth & Environment 3:. https://doi.org/10.1038/s43247-022-00517-3
- Dang C, Segal-Rozenhaimer M, Che H, et al (2022) Biomass burning and marine aerosol processing over the southeast Atlantic Ocean: a TEM single-particle analysis. Atmospheric Chemistry and Physics 22:9389–9412. https://doi.org/10.5194/acp-22-9389-2022
- Sedlacek AJ, Lewis ER, Onasch TB, et al (2022) Using the Black Carbon Particle Mixing State to Characterize the Lifecycle of Biomass Burning Aerosols. Environmental Science & Technology. https://doi.org/10.1021/acs.est.2c03851
- Zhang L, Segal-Rozenhaimer M, Che H, et al (2022) Light absorption by brown carbon over the South-East Atlantic Ocean. Atmospheric Chemistry and Physics 22:9199–9213. https://doi.org/10.5194/acp-22-9199-2022
- Adachi K, Dibb JE, Scheuer E, et al (2022) Fine Ash-Bearing Particles as a Major Aerosol Component in Biomass Burning Smoke. Journal of Geophysical Research: Atmospheres 127:. https://doi.org/10.1029/2021jd035657
- Zawadowicz MA, Suski K, Liu J, Pekour M, Fast J, Mei F, Sedlacek AJ, Springston S, Wang Y, Zaveri RA, Wood R, Wang J, Shilling JE (2021) Aircraft measurements of aerosol and trace gas chemistry in the eastern North Atlantic. Atmospheric Chemistry and Physics 21:7983–8002. doi: 10.5194/acp-21-7983-2021
- Hodshire AL, Ramnarine E, Akherati A, Alvarado ML, Farmer DK, Jathar SH, Kreidenweis SM, Lonsdale CR, Onasch TB, Springston SR, Wang J, Wang Y, Kleinman LI, Sedlacek III AJ, Pierce JR (2021) Dilution impacts on smoke aging: evidence in Biomass Burning Observation Project (BBOP) data. Atmospheric Chemistry and Physics 21:6839–6855. doi: 10.5194/acp-21-6839-2021
- Howell SG, Freitag S, Dobracki A, et al (2021) Undersizing of aged African biomass burning aerosol by an ultra-high-sensitivity aerosol spectrometer. Atmospheric Measurement Techniques 14:7381–7404. https://doi.org/10.5194/amt-14-7381-2021
- Miller RM, McFarquhar GM, Rauber RM, et al (2021) Observations of supermicron-sized aerosols originating from biomass burning in southern Central Africa. Atmospheric Chemistry and Physics 21:14815–14831. https://doi.org/10.5194/acp-21-14815-2021
- Adachi K, Oshima N, Gong Z, de Sá S, Bateman AP, Martin ST, de Brito JF, Artaxo P, Cirino GG, Sedlacek III AJ, Buseck PR (2020) Mixing states of Amazon-basin aerosol particles transported over long distances using transmission electron microscopy. doi: 10.5194/acp-2020-452
- Junghenn Noyes K, Kahn R, Sedlacek A, Kleinman L, Limbacher J, Li Z (2020) Wildfire Smoke Particle Properties and Evolution, from Space-Based Multi-Angle Imaging. Remote Sensing 12:769. doi: 10.3390/rs12050769
- Presser C, Nazarian A, Chand D, Conny JM, Sedlacek A, Hubbe JM (2020) Simultaneous transmission/absorption photometry of particle-laden filters from wildland fires during the Biomass Burning Observation Project (BBOP) field campaign. Journal of Aerosol Science 150:105614. doi: 10.1016/j.jaerosci.2020.105614
- Fierce L, Onasch TB, Cappa CD, Mazzoleni C, China S, Bhandari J, Davidovits P, Fischer DA, Helgestad T, Lambe AT, Sedlacek AJ, Smith GD, Wolff L (2020) Radiative absorption enhancements by black carbon controlled by particle-to-particle heterogeneity in composition. Proceedings of the National Academy of Sciences 117:5196–5203. doi: 10.1073/pnas.1919723117
- Laing JR, Jaffe DA, Sedlacek, III AJ (2020) Comparison of Filter-based Absorption Measurements of Biomass Burning Aerosol and Background Aerosol at the Mt. Bachelor Observatory. Aerosol and Air Quality Research 20:663–678. doi: 10.4209/aaqr.2019.06.0298
- Zheng G, Sedlacek AJ, Aiken AC, Feng Y, Watson TB, Raveh-Rubin S, Uin J, Lewis ER, Wang J (2020) Long-range transported North American wildfire aerosols observed in marine boundary layer of eastern North Atlantic. Environment International 139:105680. doi: 10.1016/j.envint.2020.105680
- Adachi K, Sedlacek AJ, Kleinman L, Springston SR, Wang J, Chand D, Hubbe JM, Shilling JE, Onasch TB, Kinase T, Sakata K, Takahashi Y, Buseck PR (2019) Spherical tarball particles form through rapid chemical and physical changes of organic matter in biomass-burning smoke. Proceedings of the National Academy of Sciences 116:19336–19341. doi: 10.1073/pnas.1900129116
- Shou C, Riemer N, Onasch TB, Sedlacek AJ, Lambe AT, Lewis ER, Davidovits P, West M (2019) Mixing state evolution of agglomerating particles in an aerosol chamber: Comparison of measurements and particle-resolved simulations. Aerosol Science and Technology 53:1229–1243. doi: 10.1080/02786826.2019.1661959
- De Sá SS, Rizzo LV, Palm BB, Campuzano-Jost P, Day DA, Yee LD, Wernis R, Isaacman-VanWertz G, Brito J, Carbone S, Liu YJ, Sedlacek A, Springston S, Goldstein AH, Barbosa HMJ, Alexander ML, Artaxo P, Jimenez JL, Martin ST (2019) Contributions of biomass-burning, urban, and biogenic emissions to the concentrations and light-absorbing properties of particulate matter in central Amazonia during the dry season. Atmospheric Chemistry and Physics 19:7973–8001. doi: 10.5194/acp-19-7973-2019
- Sedlacek AJ, Onasch TB, Nichman L, Lewis ER, Davidovits P, Freedman A, Williams L (2018) Formation of refractory black carbon by SP2-induced charring of organic aerosol. Aerosol Science and Technology 52:1345–1350. doi: 10.1080/02786826.2018.1531107
- Zhang Q, Zhou S, Collier S, Jaffe D, Onasch T, Shilling J, Kleinman L, Sedlacek A (2018) Understanding Composition, Formation, and Aging of Organic Aerosols in Wildfire Emissions via Combined Mountain Top and Airborne Measurements. Multiphase Environmental Chemistry in the Atmosphere 363–385. doi: 10.1021/bk-2018-1299.ch018
- De Sá SS, Palm BB, Campuzano-Jost P, Day DA, Hu W, Isaacman-VanWertz G, Yee LD, Brito J, Carbone S, Ribeiro IO, Cirino GG, Liu Y, Thalman R, Sedlacek A, Funk A, Schumacher C, Shilling JE, Schneider J, Artaxo P, Goldstein AH, Souza RAF, Wang J, McKinney KA, Barbosa H, Alexander ML, Jimenez JL, Martin ST (2018) Urban influence on the concentration and composition of submicron particulate matter in central Amazonia. Atmospheric Chemistry and Physics 18:12185–12206. doi: 10.5194/acp-18-12185-2018
- Forestieri SD, Helgestad TM, Lambe A, Renbaum-Wolff L, Lack DA, Massoli P, Cross ES, Dubey MK, Mazzoleni C, Olfert J, Freedman A, Davidovits P, Onasch TB, Cappa CD (2018) Measurement and modeling of the multi-wavelength optical properties ofuncoated flame-generated soot. doi: 10.5194/acp-2018-306
- Sedlacek III AJ, Buseck PR, Adachi K, Onasch TB, Springston SR, Kleinman L (2018) Formation and evolution of tar balls from northwestern US wildfires. Atmospheric Chemistry and Physics 18:11289–11301. doi: 10.5194/acp-18-11289-2018
- Kassianov E, Berg L, Pekour M, Barnard J, Chand D, Comstock J, Flynn C, Sedlacek A, Shilling J, Telg H, Tomlinson J, Zelenyuk A, Fast J (2018) A Closure Study of Total Scattering Using Airborne In Situ Measurements from the Winter Phase of TCAP. Atmosphere 9:228. doi: 10.3390/atmos9060228
- Zuidema P, Sedlacek AJ, Flynn C, Springston S, Delgadillo R, Zhang J, Aiken AC, Koontz A, Muradyan P (2018) The Ascension Island Boundary Layer in the Remote Southeast Atlantic is Often Smoky. Geophysical Research Letters 45:4456–4465. doi: 10.1002/2017gl076926
- Creamean JM, Maahn M, de Boer G, McComiskey A, Sedlacek AJ, Feng Y (2018) The influence of local oil exploration and regional wildfires on summer 2015 aerosol over the North Slope of Alaska. Atmospheric Chemistry and Physics 18:555–570. doi: 10.5194/acp-18-555-2018
- Adachi K, Sedlacek AJ, Kleinman L, Chand D, Hubbe JM, Buseck PR (2017) Volume changes upon heating of aerosol particles from biomass burning using transmission electron microscopy. Aerosol Science and Technology 52:46–56. doi: 10.1080/02786826.2017.1373181
- Bateman AP, Gong Z, Harder TH, de Sá SS, Wang B, Castillo P, China S, Liu Y, O'Brien RE, Palm BB, Shiu H-W, Cirino GG, Thalman R, Adachi K, Alexander ML, Artaxo P, Bertram AK, Buseck PR, Gilles MK, Jimenez JL, Laskin A, Manzi AO, Sedlacek A, Souza RAF, Wang J, Zaveri R, Martin ST (2017) Anthropogenic influences on the physical state of submicron particulate matter over a tropical forest. Atmospheric Chemistry and Physics 17:1759–1773. doi: 10.5194/acp-17-1759-2017
- Liu X, Huey LG, Yokelson RJ, Selimovic V, Simpson IJ, Müller M, Jimenez JL, Campuzano-Jost P, Beyersdorf AJ, Blake DR, Butterfield Z, Choi Y, Crounse JD, Day DA, Diskin GS, Dubey MK, Fortner E, Hanisco TF, Hu W, King LE, Kleinman L, Meinardi S, Mikoviny T, Onasch TB, Palm BB, Peischl J, Pollack IB, Ryerson TB, Sachse GW, Sedlacek AJ, Shilling JE, Springston S, St. Clair JM, Tanner DJ, Teng AP, Wennberg PO, Wisthaler A, Wolfe GM (2017) Airborne measurements of western U.S. wildfire emissions: Comparison with prescribed burning and air quality implications. Journal of Geophysical Research: Atmospheres 122:6108–6129. doi: 10.1002/2016jd026315
- Thalman R, de Sá SS, Palm BB, Barbosa HMJ, Pöhlker ML, Alexander ML, Brito J, Carbone S, Castillo P, Day DA, Kuang C, Manzi A, Ng NL, Sedlacek III AJ, Souza R, Springston S, Watson T, Pöhlker C, Pöschl U, Andreae MO, Artaxo P, Jimenez JL, Martin ST, Wang J (2017) CCN activity and organic hygroscopicity of aerosols downwind of an urban region in central Amazonia: seasonal and diel variations and impact of anthropogenic emissions. Atmospheric Chemistry and Physics 17:11779–11801. doi: 10.5194/acp-17-11779-2017
- Zhou S, Collier S, Jaffe DA, Briggs NL, Hee J, Sedlacek III AJ, Kleinman L, Onasch TB, Zhang Q (2017) Regional influence of wildfires on aerosol chemistry in the western US and insights into atmospheric aging of biomass burning organic aerosol. Atmospheric Chemistry and Physics 17:2477–2493. doi: 10.5194/acp-17-2477-2017
- Berg LK, Fast JD, Barnard JC, Burton SP, Cairns B, Chand D, Comstock JM, Dunagan S, Ferrare RA, Flynn CJ, Hair JW, Hostetler CA, Hubbe J, Jefferson A, Johnson R, Kassianov EI, Kluzek CD, Kollias P, Lamer K, Lantz K, Mei F, Miller MA, Michalsky J, Ortega I, Pekour M, Rogers RR, Russell PB, Redemann J, Sedlacek AJ, Segal-Rosenheimer M, Schmid B, Shilling JE, Shinozuka Y, Springston SR, Tomlinson JM, Tyrrell M, Wilson JM, Volkamer R, Zelenyuk A, Berkowitz CM (2016) The Two-Column Aerosol Project: Phase I—Overview and impact of elevated aerosol layers on aerosol optical depth. Journal of Geophysical Research: Atmospheres 121:336–361. doi: 10.1002/2015jd023848
- Collier S, Zhou S, Onasch TB, Jaffe DA, Kleinman L, Sedlacek AJ, Briggs NL, Hee J, Fortner E, Shilling JE, Worsnop D, Yokelson RJ, Parworth C, Ge X, Xu J, Butterfield Z, Chand D, Dubey MK, Pekour MS, Springston S, Zhang Q (2016) Regional Influence of Aerosol Emissions from Wildfires Driven by Combustion Efficiency: Insights from the BBOP Campaign. Environmental Science & Technology 50:8613–8622. doi: 10.1021/acs.est.6b01617
- Fast JD, Berg LK, Zhang K, Easter RC, Ferrare RA, Hair JW, Hostetler CA, Liu Y, Ortega I, Sedlacek A, Shilling JE, Shrivastava M, Springston SR, Tomlinson JM, Volkamer R, Wilson J, Zaveri RA, Zelenyuk A (2016) Model representations of aerosol layers transported from North America over the Atlantic Ocean during the Two-Column Aerosol Project. Journal of Geophysical Research: Atmospheres 121:9814–9848. doi: 10.1002/2016jd025248
- Kleinman L, Kuang C, Sedlacek A, Senum G, Springston S, Wang J, Zhang Q, Jayne J, Fast J, Hubbe J, Shilling J, Zaveri R (2016) What do correlations tell us about anthropogenic–biogenic interactions and SOA formation in the Sacramento plume during CARES? Atmospheric Chemistry and Physics 16:1729–1746. doi: 10.5194/acp-16-1729-2016
- Nasiri S, Williamson A, Cappa CD, Kotamarthi DR, Sedlacek AJ, Flynn C, Lewis E, McComiskey A, Riemer N (2016) Absorbing Aerosols Workshop, January 20-21, 2016. doi: 10.2172/1336076
- Wang X, Heald CL, Sedlacek AJ, de Sá SS, Martin ST, Alexander ML, Watson TB, Aiken AC, Springston SR, Artaxo P (2016) Deriving Brown Carbon from Multi-Wavelength Absorption Measurements: Method and Application to AERONET and Surface Observations. doi: 10.5194/acp-2016-237
- Zhou S, Collier S, Xu J, Mei F, Wang J, Lee Y-N, Sedlacek AJ, Springston SR, Sun Y, Zhang Q (2016) Influences of upwind emission sources and atmospheric processing on aerosol chemistry and properties at a rural location in the Northeastern U.S. Journal of Geophysical Research: Atmospheres 121:6049–6065. doi: 10.1002/2015jd024568
- Kassianov E, Berg L, Pekour M, Barnard J, Chand D, Flynn C, Ovchinnikov M, Sedlacek A, Schmid B, Shilling J, Tomlinson J, Fast J (2015) Airborne Aerosol in Situ Measurements during TCAP: A Closure Study of Total Scattering. Atmosphere 6:1069–1101. doi: 10.3390/atmos6081069
- Sedlacek AJ, Lewis ER, Onasch TB, Lambe AT, Davidovits P (2015) Investigation of Refractory Black Carbon-Containing Particle Morphologies Using the Single-Particle Soot Photometer (SP2). Aerosol Science and Technology 49:872–885. doi: 10.1080/02786826.2015.1074978
Awards & Recognition
- U.S. Patent 6,606,677: Mini-Raman Sensor for the Remote, Standoff Sensing of Chemical/Biological Substances and Method for Sensing Same, Ray, Mark D., and Arthur J. Sedlacek, III, granted 6/22/04
- DOE Certificate of Appreciation 1998
- Distinguished BNL Research and Development Award – 1998

Brookhaven National Laboratory
Environmental and Climate Sciences Department
Bldg. 815, Room 1-46
P.O. Box 5000
Upton, NY 11973-5000
(631) 344-2404
sedlacek@bnl.gov