title: Observational studies and a statistical early warning of surface ozone pollution in Tangshan, the largest heavy industry city of North China.
abstract: Continuous measurements of surface ozone (O3) and nitrogen oxides (NOX) at an urban site (39°37'N, 118°09'E) in Tangshan, the largest heavy industry city of North China during summertime from 2008 to 2011 are presented. The pollution of O3 was serious in the city. The daily maximum 1 h means (O3_1-hr max) reached 157 ± 55, 161 ± 54, 120 ± 50, and 178 ± 75 μg/m3 corresponding to an excess over the standard rates of 21%, 27%, 10%, and 40% in 2008-2011, respectively. The total oxidant level (OX = O3 + NO2) was high, with seasonal average concentrations up to 100 μg/m3 in summer. The level of OX at a given location was made up of NOX-independent and NOX-dependent contributions. The independent part can be considered as a regional contribution and was about 100 μg/m3 in Tangshan. Statistical early warning analysis revealed that the O3 levels would exceed the standard rate by 50% on the day following a day when the daily average ozone concentration (O3_mean) exceeded 87 μg/m3 and the daily maximum temperature (T_max) exceeded 29 °C. The exceed-standard rate would reach 80% when O3_mean and T_max exceeded 113 μg/m3 and 31 °C. Similarly, the exceed-standard rate would reach 100% when O3_mean and T_max exceeded 127 μg/m3 and 33 °C, respectively.
authors.affiliation: College of Atmospheric Science, Lanzhou University, Lanzhou, Gansu 730000, China. lipei@dq.cern.ac.cn
authors.forename: Pei
authors.initials: P
authors.lastname: Li
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Xin
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Bai
authors.forename: Yuesi
authors.initials: Y
authors.lastname: Wang
authors.forename: Shigong
authors.initials: S
authors.lastname: Wang
authors.forename: Shixi
authors.initials: S
authors.lastname: Liu
authors.forename: Xiaoxin
authors.initials: X
authors.lastname: Feng
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000517:prevention & control / Q000706:statistics & numerical data*; D002681:China; D002947:Cities; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D007221:Industry; D009589:Nitrogen Oxides / Q000032:analysis; D010126:Ozone / Q000032:analysis*; D012044:Regression Analysis; D012621:Seasons; D013696:Temperature; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D010126:Ozone