Surface ozone trend details and interpretations in Beijing, 2001–2006
Open Access
- 20 November 2009
- journal article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 9 (22), 8813-8823
- https://doi.org/10.5194/acp-9-8813-2009
Abstract
Beijing is a megacity situated in the rapidly developing Beijing-Tianjin-Hebei region of northern China. In this study, we analyze data on ozone and nitrogen oxide levels obtained at six urban sites in Beijing between the months of July and September. Our goal is to investigate average trends and interpretations over the 2001–2006 period. Average concentrations of NOx (NOx=NO+NO2), O3, and Ox (Ox=O3+NO2) were 49.2±5.9 ppbv, 26.6±2.8 ppbv, and 60.3±1.9 ppbv, respectively. NOx concentrations decreased linearly at a rate of 3.9±0.5 ppbv/yr after 2002, while ozone concentrations increased at a rate of 1.1±0.5 ppbv/yr during 2001–2006, and Ox concentrations remained nearly constant. The reduction of NOx emissions and elevated non-methane hydrocarbon (NMHCs) emissions may have contributed to the increased O3 concentrations in Beijing. When the contributions from Beijing's urban and surrounding areas were disaggregated via trajectory cluster analysis, daily maximum and average Ox concentrations attributable to Beijing's local emissions increased linearly at rates of 1.3±0.6 ppbv/yr and 0.8±0.6 ppbv/yr, while the Ox concentrations attributable to regional areas decreased linearly at rates of 0.6±0.3 ppbv/yr and 0.5±0.3 ppbv/yr, respectively. The decrease in Ox concentrations of the surrounding areas was found to counteract increasing Beijing urban Ox production, leading to nearly constant Ox concentrations in the Beijing region over the study period. Our results may be helpful for redefining government strategies to control the photochemical formation of air pollutants in the Beijing region. Our conclusions have relevance for developing megacities worldwide.This publication has 23 references indexed in Scilit:
- Global Air Quality and PollutionScience, 2003
- Analysis of the relationship between ambient levels of O3, NO2 and NO as a function of NOx in the UKAtmospheric Environment, 2001
- Surface ozone trends in Hong Kong in 1985–1995Environment International, 2001
- Ozone and other secondary photochemical pollutants: chemical processes governing their formation in the planetary boundary layerAtmospheric Environment, 2000
- Climatological aspects of the daytime mixing height in Buenos Aires city, ArgentinaAtmospheric Environment, 1998
- Computation, accuracy and applications of trajectories—A review and bibliographyAtmospheric Environment, 1998
- Extending cluster analysis—synoptic meteorology links to characterise chemical climates at six northwest European monitoring stationsAtmospheric Environment, 1995
- Important meteorological parameters for ozone episodes experienced in the Taipei basinAtmospheric Environment, 1994
- Assessing recent surface ozone concentrations in the U.K.Atmospheric Environment, 1994
- The Scree Test For The Number Of FactorsMultivariate Behavioral Research, 1966