Impact of improved representation of VOC emissions and production of NOx reservoirs on modeled urban ozone production

• DOI: 10.5194/egusphere-2024-951
• Publication Date: 2024-04-08T09:24:55Z
• Authors: Katherine R. Travis; Benjamin A. Nault; James H. Crawford; Kelvin H. Bates; Donald R. Blake; Ronald C. Cohen; Alan Fried; Samuel R. Hall; L. Greg Huey; Young Ro Lee; Simone Meinardi; Kyung-Eun Min; Isobel J. Simpson; Kirk Ullman
• Keywords: Isoprene; Emission inventory; Volatile organic compound; Peroxyacetyl nitrate

Abstract. The fraction of urban volatile organic compounds (VOC) emissions attributable to fossil fuel combustion has been declining in many parts the world, resulting a need better constrain other anthropogenic sources these emissions. During National Institute Environmental Research (NIER) and Aeronautics Space Administration (NASA) Korea-United States Air Quality (KORUS-AQ) field study Seoul, South Korea during May–June 2016, air quality models underestimated ozone, formaldehyde, peroxyacetyl nitrate (PAN) indicating an underestimate VOCs inventory. Here, we use aircraft observations interpreted with GEOS-Chem chemical transport model assess for increases VOC We find that largest are associated products, liquefied petroleum gas (LPG) natural emissions, long-range transport. Revising chemistry match observed speciation together increasing species increased calculated OH reactivity by +2 s-1 ozone production 2 ppb hr-1. Ozone 6 below km 9 at surface, formaldehyde acetaldehyde 30 % 120 aloft, respectively, all agreement observations. larger increase was attributed ethanol which found be as important isoprene or alkenes. largely resolved PAN bias. additional unmeasured however indicated remaining bias -1 57 52 higher peroxynitrates (PNs) alkyl nitrates (ANs), respectively. added represent six PNs from but were unable account majority missing PNs. However, four modeled concentrations similar commonly measured (>2 PAN) should future campaigns. hypothesize oxygenated (OVOCs) such >C5 aldehydes cooking and/or alkenes products could produce both ANs improve biases. Emerging research on will soon allow modeling their impact local regional photochemistry.