Evaluating the Impact of Emissions Regulations on the Emissions Reduction During the 2015 China Victory Day Parade With an Ensemble Square Root Filter

Abstract

In order to guarantee good air quality for the 15th International Association of Athletics Federations World Championships (22–30 August) and the China Victory Day parade (3 September) in Beijing, a series of comprehensive emissions regulations were implemented in Beijing and the surrounding provinces from 20 August to 3 September 2015. During this period, the intensity of the emissions regulation was enhanced step by step in the run‐up to the event. This period therefore allowed us to quantitatively estimate the reduction in emissions as a result of the emissions regulations under different intensity and strategy scenarios. The ensemble square root filter was employed to optimize the initial conditions and the emissions simultaneously. Numerical results showed that the variations of the anthropogenic emissions before, during, and after the emissions regulations were reasonably simulated. The updated emissions were about 80% and 50% of the prior anthropogenic emissions during the regular‐ and stringent‐regulations periods, respectively. As a result, the PM2.5 concentrations consistently reduced during the regulations period, and the largest reduction occurred under the stringent‐regulations period. Sensitivity simulations forced by the averaged emissions before the regulations and during the regular‐ and stringent‐regulation periods further highlighted the valuable impacts of emissions regulations, under different strategy and intensity scenarios, on the improvement of air quality. More intense emissions regulation will lead to a greater reduction in PM2.5 concentrations.

Assessment of the Meteorological Impact on Improved PM2.5 Air Quality Over North China During 2016–2019 Based on a Regional Joint Atmospheric Composition Reanalysis Data‐Set

“…As shown in Figure 2, the observations, background, and reanalyzes were generally in good agreement, suggesting that the reanalysis data‐set is well calibrated and has an acceptable performance. Moreover, the JDAS performed well for both major meteorological variables and chemical variables, and particularly in reproducing the ridge and trough of PM 2.5 concentrations during both polluted and clean episodes (Chu et al., 2018; Peng et al., 2018). In general, comprehensive evaluation indicates that the JDAS provides a reasonable representation of the current atmosphere, making it suitable for retrospective multi‐year analyses.…”

Study on the variation of air pollutant concentration and its formation mechanism during the COVID-19 period in Wuhan

“…Many emission reduction campaigns were conducted in China to avoid air pollution, with Wang et al (2009) , Yang et al (2010) and Li et al (2011) having done a study about the emission reduction campaigns during the “Olympics Blue” in 2008. Sun et al (2016) , Huang et al (2015) and Xie et al (2016) completed studies about the “APEC Blue” in 2014 and Han et al (2016) , Chu et al (2018) and Ren et al (2019) conducted a study about the “Parade Blue” in 2015. In these cases, China closed factories, industrial plants, construction sites, gas stations and kept vehicles off of the road in order to avoid air pollution, with the emission reduction campaigns proving to be effective.…”

NOx Emission Changes Over China During the COVID‐19 Epidemic Inferred From Surface NO2 Observations

“…Feng et al (2020) inferred the CO emissions changes over China during the “Action Plan” using surface CO observations. Chu et al (2018) and Ding et al (2015) estimated PM 2.5 and NO x emission changes during the 2015 China Victory Day parade and the 2014 Youth Olympic Games by assimilating surface PM 2.5 and OMI retrievals, respectively.…”