title: [Characteristics of atmospheric NO2 in the Beijing-Tianjin-Hebei region and the Yangtze River Delta analyzed by satellite and ground observations].
abstract: The interannual variability of NO2 levels in two major Chinese economic regions, the Beijing-Tianjin-Hebei (BTH) economic circle and the Yangtze River Delta (YRD), were studied using multiple years of OMI-retrieved NO2 columns and ground measurements. The NO2 columns were comparable in the two regions, which were - 50% higher than the BTH and YRD regional background and two times higher than the Asia-Europe continental background. Satellite data showed that the high NO2 regions scattered around Beijing and Shanghai in summer, and the coverage of high NO2 regions increased in spring and merged in winter, affecting the entire eastern China. Ground level NO2 concentrations in the urban centers of Beijing and Shanghai were also comparable, which were - 10 times greater than the regional background and 1 000 times higher than the Asia-Europe continental background. As industries gradually migrated out of the urban centers, the NO2 concentrations in Beijing and Shanghai decreased, but the regional background NO2 concentration in BTH and YRD increased. It reflected in part the impact of NO2 emission reductions related to fossil fuel combustion as a result of air quality control measures in BTH and YRD. NO2 levels during the Beijing 2008 Olympic Games and the Shanghai World Expo 2010 decreased temporarily, but bounced back quickly afterwards, indicating that sustainable air quality improvement can only be achieved through long-term regional efforts.
authors: College of Life and Environmental Science, Minzu University of China, Beijing 100081, China. wy1972@126.com
authors: Ying
authors: Y
authors: Wang
authors: Ling-Jun
authors: LJ
authors: Li
authors: Yang
authors: Y
authors: Liu
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000032:analysis; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D005579:Fossil Fuels; D009585:Nitrogen Dioxide / Q000032:analysis*; D058998:Remote Sensing Technology / Q000295:instrumentation / Q000379:methods
chemical_list: D000393:Air Pollutants; D005579:Fossil Fuels; D009585:Nitrogen Dioxide