title: [Effects of synoptic type on surface ozone pollution in Beijing].
abstract: Ozone (O), influenced by meteorological factors, is a primary gaseous photochemical pollutant during summer to fall in Beijing' s urban ambient. Continuous monitoring during July to September in 2008 was carried out at four sites in Beijing. Analyzed with synoptic type, the results show that the ratios of pre-low cylonic (mainly Mongolia cyclone) and pre-high anticylonic to total weather conditions are about 42% and 20%, illustrating the high-and low-ozone episodes, respectively. At the pre-low cylonic conditions, high temperature, low humidity, mountain and valley winds caused by local circulation induce average hourly maximum ozone concentration (volume fraction) up to 102.2 x 10(-9), negative correlated with atmospheric pressure with a slope of -3.4 x 10(-9) Pa(-1). The time of mountain wind changed to valley wind dominates the diurnal time of maximum ozone, generally around 14:00. At the pre-high anticylonic conditions, low temperature, high humidity and systematic north wind induce average hourly maximum ozone concentration (volume fraction) only 49.3 x 10(-9), the diurnal time of maximum ozone is deferred by continuous north wind till about 16:00. The consistency of photochemical pollution in Beijing region shows that good correlation exists between synoptic type and ozone concentration. Therefore, getting an eye on the structure and evolution of synoptic type is of great significances for forecasting the photochemical pollution.
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. tgq@dq.cern
authors.forename: Gui-qian
authors.initials: GQ
authors.lastname: Tang
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Xiao-ke
authors.initials: XK
authors.lastname: Wang
authors.forename: Jin-yuan
authors.initials: JY
authors.lastname: Xin
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.forename: Li-li
authors.initials: LL
authors.lastname: Wang
authors.forename: Yu-fen
authors.initials: YF
authors.lastname: Ren
authors.forename: Yue-Si
authors.initials: YS
authors.lastname: Wang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere; D002681:China; D004784:Environmental Monitoring / Q000379:methods; D006813:Humidity; D010083:Oxidants, Photochemical / Q000032:analysis*; D010126:Ozone / Q000032:analysis*; D012621:Seasons; D013696:Temperature; D014919:Wind
chemical_list: D000393:Air Pollutants; D010083:Oxidants, Photochemical; D010126:Ozone