<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ma, Y. F.</style></author><author><style face="normal" font="default" size="100%">Lu, K. D.</style></author><author><style face="normal" font="default" size="100%">Chou, C. C. K.</style></author><author><style face="normal" font="default" size="100%">Li, X. Q.</style></author><author><style face="normal" font="default" size="100%">Zhang, Y. H.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Strong deviations from the NO-NO2-O-3 photostationary state in the Pearl River Delta: Indications of active peroxy radical and chlorine radical chemistry</style></title><secondary-title><style face="normal" font="default" size="100%">Atmospheric EnvironmentAtmospheric Environment</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Atmos Environ</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">airborne observations</style></keyword><keyword><style  face="normal" font="default" size="100%">atmospheric chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">boundary-layer</style></keyword><keyword><style  face="normal" font="default" size="100%">chlorine chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">leighton ratio</style></keyword><keyword><style  face="normal" font="default" size="100%">ozone production</style></keyword><keyword><style  face="normal" font="default" size="100%">pearl river delta</style></keyword><keyword><style  face="normal" font="default" size="100%">peroxy radical</style></keyword><keyword><style  face="normal" font="default" size="100%">racm2</style></keyword><keyword><style  face="normal" font="default" size="100%">reactive chlorine</style></keyword><keyword><style  face="normal" font="default" size="100%">regional air-quality</style></keyword><keyword><style  face="normal" font="default" size="100%">relative-humidity</style></keyword><keyword><style  face="normal" font="default" size="100%">tropospheric chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">united-states</style></keyword><keyword><style  face="normal" font="default" size="100%">urban atmosphere</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2017</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Aug</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">163</style></volume><pages><style face="normal" font="default" size="100%">22-34</style></pages><isbn><style face="normal" font="default" size="100%">1352-2310</style></isbn><language><style face="normal" font="default" size="100%">English</style></language><abstract><style face="normal" font="default" size="100%">Simultaneous measurements of meteorological data, trace gases, and volatile organic compounds were made in two regional sites, viz. Backgarden and Kaiping, in the Pearl River Delta (PRD) during summer and autumn, respectively. The strong deviations from the NO-NO2-O-3 Photostationary State, quantified by the leighton ratios, are carefully deduced through a comprehensive data set consist of the high-quality measurements of NO, NO2, O-3 and JNoz as well as the peroxy radical measurements. This is the first report of the Leighton ratio in China, with relatively high recorded values of 2.3 +/- 0.4 (Backgarden) and 3.1 +/- 1.4 (Kaiping), suggesting a strongly oxidising atmosphere in the PRD, typical of the ozone pollution season. A sensitivity analysis using a zero-dimensional chemical box model based on the regional atmospheric chemistry mechanism, version 2 (RACM2) constrained by the experimental measurements, indicated that peroxy radicals account for 70 (Backgarden) and 66% (Kaiping) of the observed positive deviations from the NOx photostationary state (characterized by a Leighton ratio of 1) on average. We consider that the remaining deviations result from neglecting the effects of chlorine chemistry, so We introduced a Cl chemistry module into RACM2, and the modelled results for Cl were as follows: 4.7 x 10(-4) pptv in Backgarden and 1.3 x 10(-3) pptv in Kaiping; these results are lower than the CI concentration derived from the NOx photostationary state. More work is required to confirm the role of additional peroxy radical sources at both high and low NOx regimes, as well as that of the halogen radicals, in perturbing the NO-NOx-O-3 cycle, which would significantly enhance trace gas removal and photochemical ozone production. (C) 2017 Elsevier Ltd. All rights reserved.</style></abstract><accession-num><style face="normal" font="default" size="100%">WOS:000404491800003</style></accession-num><notes><style face="normal" font="default" size="100%">Ez1stTimes Cited:0Cited References Count:63</style></notes><auth-address><style face="normal" font="default" size="100%">Peking Univ, Coll Environm Sci &amp; Engn, State Key Joint Lab Environm Simulat &amp; Pollut Con, Beijing 100871, Peoples R ChinaAcad Sinica, Res Ctr Environm Changes, Taipei 11529, TaiwanChinese Res Inst Environm Sci, State Key Lab Environm Criteria &amp; Risk Assessment, Beijing 100012, Peoples R China</style></auth-address></record></records></xml>