Why do Models Overestimate Surface Ozone in the Southeastern United States?

Autor: Travis KR; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA., Jacob DJ; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA.; Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA., Fisher JA; Centre for Atmospheric Chemistry, School of Chemistry, University of Wollongong, Wollongong, NSW, Australia.; School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW, Australia., Kim PS; Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA., Marais EA; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA., Zhu L; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA., Yu K; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA., Miller CC; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA., Yantosca RM; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA., Sulprizio MP; Department of Earth and Planetary Sciences and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA., Thompson AM; NASA Goddard Space Flight Center, Greenbelt, Maryland, USA., Wennberg PO; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.; Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA., Crounse JD; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA., St Clair JM; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA., Cohen RC; Department of Chemistry, University of California, Berkeley, CA, USA., Laughner JL; Department of Chemistry, University of California, Berkeley, CA, USA., Dibb JE; Earth System Research Center, University of New Hampshire, Durham, NH, USA., Hall SR; Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO, USA., Ullmann K; Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO, USA., Wolfe GM; Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA.; Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD, USA., Pollack IB; Atmospheric Science Department, Colorado State University, Fort Collins, Colorado, USA., Peischl J; University of Colorado, Cooperative Institute for Research in Environmental Sciences, Boulder, CO, USA.; NOAA, Division of Chemical Science, Earth Systems Research Lab, Boulder, CO USA., Neuman JA; University of Colorado, Cooperative Institute for Research in Environmental Sciences, Boulder, CO, USA.; NOAA, Division of Chemical Science, Earth Systems Research Lab, Boulder, CO USA., Zhou X; Department of Environmental Health and Toxicology, School of Public Health, State University of New York at Albany, Albany, New York, USA.; Wadsworth Center, New York State Department of Health, Albany, New York, USA.
Jazyk: angličtina
Zdroj: Atmospheric chemistry and physics [Atmos Chem Phys] 2016; Vol. 16 (21), pp. 13561-13577. Date of Electronic Publication: 2016 Nov 01.
DOI: 10.5194/acp-16-13561-2016
Abstrakt: Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NO x ≡ NO + NO 2 ) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from the SEAC 4 RS aircraft campaign in August and September 2013, interpreted with the GEOS-Chem chemical transport model at 0.25°×0.3125° horizontal resolution, to better understand the factors controlling surface ozone in the Southeast US. We find that the National Emission Inventory (NEI) for NO x from the US Environmental Protection Agency (EPA) is too high. This finding is based on SEAC 4 RS observations of NO x and its oxidation products, surface network observations of nitrate wet deposition fluxes, and OMI satellite observations of tropospheric NO 2 columns. Our results indicate that NEI NO x emissions from mobile and industrial sources must be reduced by 30-60%, dependent on the assumption of the contribution by soil NO x emissions. Upper tropospheric NO 2 from lightning makes a large contribution to satellite observations of tropospheric NO 2 that must be accounted for when using these data to estimate surface NO x emissions. We find that only half of isoprene oxidation proceeds by the high-NO x pathway to produce ozone; this fraction is only moderately sensitive to changes in NO x emissions because isoprene and NO x emissions are spatially segregated. GEOS-Chem with reduced NO x emissions provides an unbiased simulation of ozone observations from the aircraft, and reproduces the observed ozone production efficiency in the boundary layer as derived from a regression of ozone and NO x oxidation products. However, the model is still biased high by 8±13 ppb relative to observed surface ozone in the Southeast US. Ozonesondes launched during midday hours show a 7 ppb ozone decrease from 1.5 km to the surface that GEOS-Chem does not capture. This bias may reflect a combination of excessive vertical mixing and net ozone production in the model boundary layer.
Databáze: MEDLINE