Comprehensive evaluations of diurnal NO2 measurements during DISCOVER-AQ 2011: effects of resolution-dependent representation of NOx emissions

J. Li; J. Li; Y. Wang; R. Zhang; C. Smeltzer; A. Weinheimer; J. Herman; K. F. Boersma; K. F. Boersma; E. A. Celarier; E. A. Celarier; E. A. Celarier; R. W. Long; J. J. Szykman; R. Delgado; A. M. Thompson; T. N. Knepp; T. N. Knepp; L. N. Lamsal; S. J. Janz; M. G. Kowalewski; X. Liu; C. R. Nowlan

doi:10.5194/acp-21-11133-2021

Atmospheric Chemistry and Physics (Jul 2021)

Comprehensive evaluations of diurnal NO2 measurements during DISCOVER-AQ 2011: effects of resolution-dependent representation of NOx emissions

J. Li,
J. Li,
Y. Wang,
R. Zhang,
C. Smeltzer,
A. Weinheimer,
J. Herman,
K. F. Boersma,
K. F. Boersma,
E. A. Celarier,
E. A. Celarier,
E. A. Celarier,
R. W. Long,
J. J. Szykman,
R. Delgado,
A. M. Thompson,
T. N. Knepp,
T. N. Knepp,
L. N. Lamsal,
S. J. Janz,
M. G. Kowalewski,
X. Liu,
C. R. Nowlan

Affiliations

J. Li: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
J. Li: now at: Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA
Y. Wang: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
R. Zhang: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
C. Smeltzer: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
A. Weinheimer: National Center for Atmospheric Research, Boulder, CO, USA
J. Herman: Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD, USA
K. F. Boersma: Royal Netherlands Meteorological Institute, De Bilt, the Netherlands
K. F. Boersma: Meteorology and Air Quality Group, Wageningen University, Wageningen, the Netherlands
E. A. Celarier: NASA Goddard Space Flight Center, Greenbelt, MD, USA
E. A. Celarier: Universities Space Research Association, Columbia, MD, USA
E. A. Celarier: now at: Digital Spec, Tyson's Corner, VA, USA
R. W. Long: National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
J. J. Szykman: National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
R. Delgado: Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD, USA
A. M. Thompson: NASA Goddard Space Flight Center, Greenbelt, MD, USA
T. N. Knepp: NASA Langley Research Center, Virginia, USA
T. N. Knepp: Science Systems and Applications, Inc., Hampton, VA, USA
L. N. Lamsal: NASA Goddard Space Flight Center, Greenbelt, MD, USA
S. J. Janz: NASA Goddard Space Flight Center, Greenbelt, MD, USA
M. G. Kowalewski: NASA Goddard Space Flight Center, Greenbelt, MD, USA
X. Liu: Atomic and Molecular Physics Division, Harvard–Smithsonian Center for Astrophysics, Cambridge, MA, USA
C. R. Nowlan: Atomic and Molecular Physics Division, Harvard–Smithsonian Center for Astrophysics, Cambridge, MA, USA

DOI: https://doi.org/10.5194/acp-21-11133-2021
Journal volume & issue: Vol. 21
pp. 11133 – 11160

Abstract

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Nitrogen oxides (NOx = NO + NO2) play a crucial role in the formation of ozone and secondary inorganic and organic aerosols, thus affecting human health, global radiation budget, and climate. The diurnal and spatial variations in NO2 are functions of emissions, advection, deposition, vertical mixing, and chemistry. Their observations, therefore, provide useful constraints in our understanding of these factors. We employ a Regional chEmical and trAnsport model (REAM) to analyze the observed temporal (diurnal cycles) and spatial distributions of NO2 concentrations and tropospheric vertical column densities (TVCDs) using aircraft in situ measurements and surface EPA Air Quality System (AQS) observations as well as the measurements of TVCDs by satellite instruments (OMI: the Ozone Monitoring Instrument; GOME-2A: Global Ozone Monitoring Experiment – 2A), ground-based Pandora, and the Airborne Compact Atmospheric Mapper (ACAM) instrument in July 2011 during the DISCOVER-AQ campaign over the Baltimore–Washington region. The model simulations at 36 and 4 km resolutions are in reasonably good agreement with the regional mean temporospatial NO2 observations in the daytime. However, we find significant overestimations (underestimations) of model-simulated NO2 (O3) surface concentrations during nighttime, which can be mitigated by enhancing nocturnal vertical mixing in the model. Another discrepancy is that Pandora-measured NO2 TVCDs show much less variation in the late afternoon than simulated in the model. The higher-resolution 4 km simulations tend to show larger biases compared to the observations due largely to the larger spatial variations in NOx emissions in the model when the model spatial resolution is increased from 36 to 4 km. OMI, GOME-2A, and the high-resolution aircraft ACAM observations show a more dispersed distribution of NO2 vertical column densities (VCDs) and lower VCDs in urban regions than corresponding 36 and 4 km model simulations, likely reflecting the spatial distribution bias of NOx emissions in the National Emissions Inventory (NEI) 2011.

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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