Integration of airborne and ground observations of nitryl chloride in the Seoul metropolitan area and the implications on regional oxidation capacity during KORUS-AQ 2016

D. Jeong; R. Seco; D. Gu; D. Gu; Y. Lee; B. A. Nault; B. A. Nault; C. J. Knote; T. Mcgee; J. T. Sullivan; J. L. Jimenez; J. L. Jimenez; P. Campuzano-Jost; P. Campuzano-Jost; D. R. Blake; D. Sanchez; A. B. Guenther; D. Tanner; L. G. Huey; R. Long; B. E. Anderson; S. R. Hall; K. Ullmann; H. Shin; S. C. Herndon; Y. Lee; D. Kim; J. Ahn; S. Kim

doi:10.5194/acp-19-12779-2019

Atmospheric Chemistry and Physics (Oct 2019)

Integration of airborne and ground observations of nitryl chloride in the Seoul metropolitan area and the implications on regional oxidation capacity during KORUS-AQ 2016

D. Jeong,
R. Seco,
D. Gu,
D. Gu,
Y. Lee,
B. A. Nault,
B. A. Nault,
C. J. Knote,
T. Mcgee,
J. T. Sullivan,
J. L. Jimenez,
J. L. Jimenez,
P. Campuzano-Jost,
P. Campuzano-Jost,
D. R. Blake,
D. Sanchez,
A. B. Guenther,
D. Tanner,
L. G. Huey,
R. Long,
B. E. Anderson,
S. R. Hall,
K. Ullmann,
H. Shin,
S. C. Herndon,
Y. Lee,
D. Kim,
J. Ahn,
S. Kim

Affiliations

D. Jeong: Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
R. Seco: Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
D. Gu: Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
D. Gu: currently at: Division of Environment and Sustainability, Hong Kong University of Science and Technology, Hong Kong, China
Y. Lee: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
B. A. Nault: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
B. A. Nault: Department of Chemistry, University of Colorado, Boulder, CO, USA
C. J. Knote: Meteorologisches Institut, Ludwig-Maximilians-Universität München, Munich, Germany
T. Mcgee: Atmospheric Chemistry and Dynamics Laboratory, NASA GSFC, Greenbelt, MD, USA
J. T. Sullivan: Atmospheric Chemistry and Dynamics Laboratory, NASA GSFC, Greenbelt, MD, USA
J. L. Jimenez: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
J. L. Jimenez: Department of Chemistry, University of Colorado, Boulder, CO, USA
P. Campuzano-Jost: Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
P. Campuzano-Jost: Department of Chemistry, University of Colorado, Boulder, CO, USA
D. R. Blake: Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
D. Sanchez: Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
A. B. Guenther: Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
D. Tanner: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
L. G. Huey: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
R. Long: Office of Research and Development, U.S. EPA, Research Triangle Park, NC, USA
B. E. Anderson: NASA Langley Research Center, Hampton, VA, USA
S. R. Hall: National Center for Atmospheric Research, Boulder, CO, USA
K. Ullmann: National Center for Atmospheric Research, Boulder, CO, USA
H. Shin: National Institute of Environmental Research, Incheon, South Korea
S. C. Herndon: Aerodyne Research Inc., Billerica, MA, USA
Y. Lee: National Institute of Environmental Research, Incheon, South Korea
D. Kim: National Institute of Environmental Research, Incheon, South Korea
J. Ahn: National Institute of Environmental Research, Incheon, South Korea
S. Kim: Department of Earth System Science, University of California, Irvine, Irvine, CA, USA

DOI: https://doi.org/10.5194/acp-19-12779-2019
Journal volume & issue: Vol. 19
pp. 12779 – 12795

Abstract

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Nitryl chloride (ClNO2) is a radical reservoir species that releases chlorine radicals upon photolysis. An integrated analysis of the impact of ClNO2 on regional photochemistry in the Seoul metropolitan area (SMA) during the Korea–United States Air Quality Study (KORUS-AQ) 2016 field campaign is presented. Comprehensive multiplatform observations were conducted aboard the NASA DC-8 and at two ground sites (Olympic Park, OP; Taehwa Research Forest, TRF), representing an urbanized area and a forested suburban region, respectively. Positive correlations between daytime Cl2 and ClNO2 were observed at both sites, the slope of which was dependent on O3 levels. The possible mechanisms are explored through box model simulations constrained with observations. The overall diurnal variations in ClNO2 at both sites appeared similar but the nighttime variations were systematically different. For about half of the observation days at the OP site the level of ClNO2 increased at sunset but rapidly decreased at around midnight. On the other hand, high levels were observed throughout the night at the TRF site. Significant levels of ClNO2 were observed at both sites for 4–5 h after sunrise. Airborne observations, box model calculations, and back-trajectory analysis consistently show that these high levels of ClNO2 in the morning are likely from vertical or horizontal transport of air masses from the west. Box model results show that chlorine-radical-initiated chemistry can impact the regional photochemistry by elevating net chemical production rates of ozone by ∼25 % in the morning.

Published in Atmospheric Chemistry and Physics

ISSN: 1680-7316 (Print); 1680-7324 (Online)
Publisher: Copernicus Publications
Country of publisher: Germany
LCC subjects: Science: Physics; Science: Chemistry
Website: http://www.atmospheric-chemistry-and-physics.net/

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