The role of meteorological conditions and pollution control strategies in reducing air pollution in Beijing during APEC 2014 and Victory Parade 2015

Abstract

Abstract. To control severe air pollution in China, comprehensive pollution control strategies have been implemented throughout the country in recent years. To evaluate the effectiveness of these strategies, the influence of meteorological conditions on levels of air pollution needs to be determined. Using the intensive air pollution control strategies implemented during the Asia-Pacific Economic Cooperation Forum in 2014 (APEC 2014) and the 2015 China Victory Day Parade (Victory Parade 2015) as examples, we estimated the role of meteorological conditions and pollution control strategies in reducing air pollution levels in Beijing. Atmospheric particulate matter of aerodynamic diameter ≤ 2.5 µm (PM 2.5 ) samples were collected and gaseous pollutants (SO 2 , NO, NO x , and O 3 ) were measured online at a site in Peking University (PKU). To determine the influence of meteorological conditions on the levels of air pollution, we first compared the air pollutant concentrations during days with stable meteorological conditions. However, there were few days with stable meteorological conditions during the Victory Parade. As such, we were unable to estimate the level of emission reduction efforts during this period. Finally, a generalized linear regression model (GLM) based only on meteorological parameters was built to predict air pollutant concentrations, which could explain more than 70 % of the variation in air pollutant concentration levels, after incorporating the nonlinear relationships between certain meteorological parameters and the concentrations of air pollutants. Evaluation of the GLM performance revealed that the GLM, even based only on meteorological parameters, could be satisfactory to estimate the contribution of meteorological conditions in reducing air pollution and, hence, the contribution of control strategies in reducing air pollution. Using the GLM, we found that the meteorological conditions and pollution control strategies contributed 30 and 28 % to the reduction of the PM 2.5 concentration during APEC and 38 and 25 % during the Victory Parade, respectively, based on the assumption that the concentrations of air pollutants are only determined by meteorological conditions and emission intensities. We also estimated the contribution of meteorological conditions and control strategies in reducing the concentrations of gaseous pollutants and PM 2.5 components with the GLMs, revealing the effective control of anthropogenic emissions.

The impact of aerosol–radiation interactions on the effectiveness of emission control measures

“…We find that during Ep1 and Ep4 the BTH areas are controlled by high pressure systems leading to stagnant air conditions and pollution accumulation, while during Ep3 (the APEC week) stronger northwestern winds associated a cold surge incursion prevail over BTH. Previous studies have also shown important influences from both emission reduction and meteorology on PM 2.5 concentrations in Beijing during the APEC week (Sun et al 2016, Zhang et al 2016, Gao et al 2017, Liang et al 2017. The observed mean PM 2.5 concentration is 48.9 μg m −3 in Beijing during APEC, and is about 60.3 μg m −3 lower than that in previous weeks (109.2 μg m −3 during 15 October-4 November 2014).…”

“…More recently, such practices have been further adopted to inhibit the formation of regional haze in Beijing and to reduce its potential damage to the society. Previous analyses of these temporary practices have shown that meteorological conditions are important for determining PM 2.5 concentration reductions and thus the effectiveness of emission control measurements (Guo et al 2016, Zhang et al 2016, Sun et al 2016, Liang et al 2017.…”

Long‐Term Trends of Persistent Synoptic Circulation Events in Planetary Boundary Layer and Their Relationships With Haze Pollution in Winter Half Year Over Eastern China

“…Many studies have documented that the main causes of air pollution in eastern China are substantial pollution emissions and unfavorable meteorological conditions, which have been, respectively, viewed as internally and externally caused factors for air pollution (Guo et al, ; Z. Q. Li et al, ; Liang et al, ; Luo et al, ; Tong et al, ; Wu et al, ; Zhu et al, ). The discharges of pollutants, including industrial emissions, biomass burning, traffic exhaust, domestic heating, and other emissions caused by human activities, have caused the deterioration of air quality in eastern China (Guo et al, ; Jiang et al, 2012; Lei et al, ; Liao et al, ; Liu et al, , ; Lu et al, ; X. Y. Zhang et al, 2012).…”

Re‐evaluating the variation in trend of haze days in the urban areas of Beijing during a recent 36‐year period

“…Local meteorological parameters, such as the relative humidity, visibility, wind speed, and precipitation, modulate the formation of polluted haze episodes (Wang and He, ; Ding and Liu, ; Zheng et al ., ; Wang and Chen, ; Liang et al, ; Miao et al, ). Figure b shows that the visibility in Beijing has been declining, with a decrease of 1.1 km/decade in terms of the daily‐averaged visibility.…”