TY - JOUR
T1 - Spherical tarball particles form through rapid chemical and physical changes of organic matter in biomass-burning smoke
AU - Adachi, Kouji
AU - Sedlacek, Arthur J.
AU - Kleinman, Lawrence
AU - Springston, Stephen R.
AU - Wang, Jian
AU - Chand, Duli
AU - Hubbe, John M.
AU - Shilling, John E.
AU - Onasch, Timothy B.
AU - Kinase, Takeshi
AU - Sakata, Kohei
AU - Takahashi, Yoshio
AU - Buseck, Peter R.
N1 - Funding Information:
ACKNOWLEDGMENTS. This research was supported by the ARM user facility, a US DOE Office of Science user facility managed by the Office of Biological and Environmental Research. We acknowledge the DOE ARM user facility for both the support to carry out the BBOP campaign and use of the G-1 research aircraft. We gratefully acknowledge the skill and safety exemplified by the ARM Aerial Facility pilots and flight staff. K.A. acknowledges the support of the Environment Research and Technology Development Fund (Grants 2-1403, 5-1605, and 2-1703) of the Environmental Restoration and Conservation Agency and the Grants-in-Aid for Scientific Research by the Japan Society for the Promotion of Science (KAKENHI) (Grants JP25740008, JP16K16188, JP16H05620, JP15H02811, JP16H01772, JP19H04259, and JP18H04134). The EELS study was supported by the National Institute for Materials Science (NIMS) microstructural characterization platform as a program of the “Nanotechnology Platform” of the Ministry of Education, Culture, Sports, Science and Technology, Japan. The STXM analysis was performed with the approval of KEK (Proposals 2013S2-003 and 2016S2-002). We acknowledge Dr. Y. Nemoto (NIMS) for his help in using the TEM (ARM), Mr. H. Suga for the STXM measurements of reference materials, and Dr. M. Pekour (Pacific Northwest National Laboratory [PNNL]) and Dr. E. Fortner (Aerodyne) for the SP-AMS measurements. A.J.S., L.K., and T.B.O. acknowledge research support by the US DOE Office of Biological & Environmental Research, Atmospheric System Research program under Contracts DE-SC0012704
Funding Information:
This research was supported by the ARM user facility, a US DOE Office of Science user facility managed by the Office of Biological and Environmental Research. We acknowledge the DOE ARM user facility for both the support to carry out the BBOP campaign and use of the G-1 research aircraft. We gratefully acknowledge the skill and safety exemplified by the ARM Aerial Facility pilots and flight staff. K.A. acknowledges the support of the Environment Research and Technology Development Fund (Grants 2-1403, 5-1605, and 2-1703) of the Environmental Restoration and Conservation Agency and the Grants-in-Aid for Scientific Research by the Japan Society for the Promotion of Science (KAKENHI) (Grants JP25740008, JP16K16188, JP16H05620, JP15H02811, JP16H01772, JP19H04259, and JP18H04134). The EELS study was supported by the National Institute for Materials Science (NIMS) microstructural characterization platform as a program of the Nanotechnology Platform of the Ministry of Education, Culture, Sports, Science and Technology, Japan. The STXM analysis was performed with the approval of KEK (Proposals 2013S2-003 and 2016S2-002). We acknowledge Dr. Y. Nemoto (NIMS) for his help in using the TEM (ARM), Mr. H. Suga for the STXM measurements of reference materials, and Dr. M. Pekour (Pacific Northwest National Laboratory [PNNL]) and Dr. E. Fortner (Aerodyne) for the SP-AMS measurements. A.J.S., L.K., and T.B.O. acknowledge research support by the US DOE Office of Biological and Environmental Research, Atmospheric System Research program under Contracts DE-SC0012704 (Brookhaven National Laboratory; A.J.S. and L.K.), KP1701000/57131 (PNNL, J.E.S.), and DE-SC0014287 (T.B.O.). D.C., J.E.S., and J.M.H. acknowledge support from the ARM user facility through PNNL, which is operated for DOE by Battelle Memorial Institute under Contract DE-AC06- 76RLO1830. P.R.B. acknowledges support from PNNL and the DOE ARM under 305 Research Subcontract 20568
Funding Information:
(Brookhaven National Laboratory; A.J.S. and L.K.), KP1701000/57131 (PNNL, J.E.S.), and DE-SC0014287 (T.B.O.). D.C., J.E.S., and J.M.H. acknowledge support from the ARM user facility through PNNL, which is operated for DOE by Battelle Memorial Institute under Contract DE-AC06-76RLO1830. P.R.B. acknowledges support from PNNL and the DOE ARM under 305 Research Subcontract 20568.
Publisher Copyright:
© 2019 National Academy of Sciences. All rights reserved.
PY - 2019/9/24
Y1 - 2019/9/24
N2 - Biomass burning (BB) emits enormous amounts of aerosol particles and gases into the atmosphere and thereby significantly influences regional air quality and global climate. A dominant particle type from BB is spherical organic aerosol particles commonly referred to as tarballs. Currently, tarballs can only be identified, using microscopy, from their uniquely spherical shapes following impaction onto a grid. Despite their abundance and potential significance for climate, many unanswered questions related to their formation, emission inventory, removal processes, and optical properties still remain. Here, we report analysis that supports tarball formation in which primary organic particles undergo chemical and physical processing within ∼3 h of emission. Transmission electron microscopy analysis reveals that the number fractions of tarballs and the ratios of N and O relative to K, the latter a conserved tracer, increase with particle age and that the more-spherical particles on the substrates had higher ratios of N and O relative to K. Scanning transmission X-ray spectrometry and electron energy loss spectrometry analyses show that these chemical changes are accompanied by the formation of organic compounds that contain nitrogen and carboxylic acid. The results imply that the chemical changes increase the particle sphericity on the substrates, which correlates with particle surface tension and viscosity, and contribute to tarball formation during aging in BB smoke. These findings will enable models to better partition tarball contributions to BB radiative forcing and, in so doing, better help constrain radiative forcing models of BB events.
AB - Biomass burning (BB) emits enormous amounts of aerosol particles and gases into the atmosphere and thereby significantly influences regional air quality and global climate. A dominant particle type from BB is spherical organic aerosol particles commonly referred to as tarballs. Currently, tarballs can only be identified, using microscopy, from their uniquely spherical shapes following impaction onto a grid. Despite their abundance and potential significance for climate, many unanswered questions related to their formation, emission inventory, removal processes, and optical properties still remain. Here, we report analysis that supports tarball formation in which primary organic particles undergo chemical and physical processing within ∼3 h of emission. Transmission electron microscopy analysis reveals that the number fractions of tarballs and the ratios of N and O relative to K, the latter a conserved tracer, increase with particle age and that the more-spherical particles on the substrates had higher ratios of N and O relative to K. Scanning transmission X-ray spectrometry and electron energy loss spectrometry analyses show that these chemical changes are accompanied by the formation of organic compounds that contain nitrogen and carboxylic acid. The results imply that the chemical changes increase the particle sphericity on the substrates, which correlates with particle surface tension and viscosity, and contribute to tarball formation during aging in BB smoke. These findings will enable models to better partition tarball contributions to BB radiative forcing and, in so doing, better help constrain radiative forcing models of BB events.
KW - Biomass burning
KW - Climate change
KW - Organic aerosol
KW - Tarball
KW - Transmission electron microscopy
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U2 - 10.1073/pnas.1900129116
DO - 10.1073/pnas.1900129116
M3 - Article
C2 - 31488715
AN - SCOPUS:85072642515
VL - 116
SP - 19336
EP - 19341
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 39
ER -