TY - JOUR
T1 - Global sensitivity analysis of ozone production and O 3-NO x-VOC limitation based on field data
AU - Chen, Shuang
AU - Brune, William H.
N1 - Funding Information:
We thank all participants in the TRAMP-2006 field campaign for sharing the data to make the model simulations possible. We gratefully acknowledge helpful discussions provided by A.M. Thompson, G.S. Young and T. Wagener. This study was supported by the NSF grant 0706821 .
PY - 2012/8
Y1 - 2012/8
N2 - Global sensitivity analysis was performed to study the effects of model uncertainties on the predictions of urban ozone production and its limitation by NO x or VOCs. Uncertainties were assigned for hundreds of model parameters including measurements used to constrain the model as well as kinetic rate coefficients and product yields of chemical reactions. Monte Carlo simulations were run using a zero-dimensional box model with 76 representative base cases of different initial conditions extracted from the measurements of a field campaign conducted in Houston, Texas. The results showed that relative uncertainty (±1σ) of ozone production exhibits a pattern of higher uncertainty at morning rush hour (about 30-40%) and lower uncertainty in the afternoon (about 20-30%). The model uncertainty comes mostly from uncertainties in chemical schemes while the uncertainties in measurements are less influential. The most important model parameters are generally associated with the amounts of acetaldehyde, the photolysis of HONO and HCHO(→HO 2), and the reactions of OH with NO 2, HO 2 with NO, and xylenes with OH. The uncertainties in these parameters could also shift the ozone-precursor relation between the NO x-sensitive and VOC-sensitive regimes. The greater values of the NO amount and the reaction rates of NO 2 + OH, NO + HO 2 and ISOP (isoprene peroxy radicals) + NO increase VOC-sensitivity, while greater values of aldehydes amounts and kinetic rate coefficients for reactions of OH with aldehydes and xylenes and of ISOP with HO 2 increase NO x-sensitivity of ozone under the studied conditions.
AB - Global sensitivity analysis was performed to study the effects of model uncertainties on the predictions of urban ozone production and its limitation by NO x or VOCs. Uncertainties were assigned for hundreds of model parameters including measurements used to constrain the model as well as kinetic rate coefficients and product yields of chemical reactions. Monte Carlo simulations were run using a zero-dimensional box model with 76 representative base cases of different initial conditions extracted from the measurements of a field campaign conducted in Houston, Texas. The results showed that relative uncertainty (±1σ) of ozone production exhibits a pattern of higher uncertainty at morning rush hour (about 30-40%) and lower uncertainty in the afternoon (about 20-30%). The model uncertainty comes mostly from uncertainties in chemical schemes while the uncertainties in measurements are less influential. The most important model parameters are generally associated with the amounts of acetaldehyde, the photolysis of HONO and HCHO(→HO 2), and the reactions of OH with NO 2, HO 2 with NO, and xylenes with OH. The uncertainties in these parameters could also shift the ozone-precursor relation between the NO x-sensitive and VOC-sensitive regimes. The greater values of the NO amount and the reaction rates of NO 2 + OH, NO + HO 2 and ISOP (isoprene peroxy radicals) + NO increase VOC-sensitivity, while greater values of aldehydes amounts and kinetic rate coefficients for reactions of OH with aldehydes and xylenes and of ISOP with HO 2 increase NO x-sensitivity of ozone under the studied conditions.
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U2 - 10.1016/j.atmosenv.2012.03.061
DO - 10.1016/j.atmosenv.2012.03.061
M3 - Article
AN - SCOPUS:84859889210
SN - 1352-2310
VL - 55
SP - 288
EP - 296
JO - Atmospheric Environment
JF - Atmospheric Environment
ER -