Analysis of the 2014 “APEC Blue” in Beijing Using More than One Decade of Satellite Observations: Lessons Learned from Radical Emission Control Measures

Abstract

During the 2014 Asia-Pacific Economic Cooperation (APEC) Economic Leaders' Meetings in Beijing, the Chinese government made significant efforts to clear Beijing's sky. The emission control measures were very effective and the improved air quality during the APEC Meetings was called the "APEC Blue". To monitor and estimate how these emission control measures affected air quality in Beijing and its five neighboring large cities (Tianjin, Shijiazhuang, Tangshan, Jinan, and Qingdao), we compared and analyzed the satellite-retrieved Aerosol Optical Thickness (AOT) products of the pre-APEC (18-31 October), APEC (1-11 November), and post-APEC periods [2002][2003][2004][2005][2006][2007][2008][2009][2010][2011][2012][2013][2014] indicated that the potential emission source regions strongly impacting air quality of Beijing were confined within central and southern Hebei as well as northern and southwestern Shandong, in correspondence with the spatial pattern of Digital Earth Model (DEM) of the study region. In addition to stringent emission control measures, back trajectory analysis indicated that the relatively favorable regional transport pattern might also have contributed to the "APEC Blue" in Beijing. These results suggest that the "APEC Blue" is a temporarily regional phenomenon; a long-term improvement of air quality in Beijing is still challenging and joint efforts of the whole region are needed.

Impact of various emission control schemes on air quality using WRF-Chem during APEC China 2014

“…Only a few studies (e.g., Streets et al, 2007;Wang et al, 2010) investigated how the emission control measures taken in Beijing affected the local air quality during the 29th Olympic Games in the summer of 2008. In addition, Meng et al (2014) attempted to figure out the impact on the air quality in Beijing of radical emission control measurements implemented during the Asia-Pacific Economic Cooperation (APEC) China 2014, which was from the perspective of satellite measurements. Although most heavy pollution events in Beijing were recorded in the fall and winter (Miao et al, 2015;San Martini et al, 2015), how the emission reduction measures play a role in mitigating the air pollution in these seasons is rarely studied.…”

Aerosol Optical Properties over Beijing during the World Athletics Championships and Victory Day Military Parade in August and September 2015

“…The purpose of the present study was to investigate the aerosol optical properties in Beijing during the period of the World Athletics Championships and Victory Day military parade in August and September 2015, based on comprehensive analysis of ground-based observation data, PM concentrations, and weather conditions. The intention was to improve understanding of the nature of aerosol optical properties during special events/periods in the Beijing region, particularly the contribution of measures to restrict traffic and reduce emissions [28][29][30][31].…”

Characterization of Chemical Composition in PM2.5 in Beijing before, during, and after a Large-Scale International Event

“…For example, northern China experienced severe haze episodes with long duration which affected unusually sizeable areas in January 2013, October 2014 and December 2015, respectively (Wang et Economic Cooperation (APEC) Summit. In order to ensure satisfactory air quality during such events, the Chinese government has implemented stringent air pollution control measures (e.g., shutting down factories, restriction of vehicles on road) in Beijing and its surrounding areas (Meng et al, 2015). These measures have provided a valuable opportunity to investigate the characteristics of regional air pollution under the effect of emission reduction.…”