The 2013 severe haze over southern Hebei, China: model evaluation, source apportionment, and policy implications

Abstract

Abstract. Extremely severe and persistent haze occurred in January 2013 over eastern and northern China. The record-breaking high concentrations of fine particulate matter (PM 2.5 ) of more than 700 µg m −3 on hourly average and the persistence of the episodes have raised widespread, considerable public concerns. During that period, 7 of the top 10 polluted cities in China were within the Hebei Province. The three cities in southern Hebei (Shijiazhuang, Xingtai, and Handan) have been listed as the top three polluted cities according to the statistics for the first half of the year 2013. In this study, the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system are applied to simulate the 2013 severe winter regional hazes in East Asia and northern China at horizontal grid resolutions of 36 and 12 km, respectively, using the Multi-resolution Emission Inventory for China (MEIC). The source contributions of major source regions and sectors to PM 2.5 concentrations in the three most polluted cities in southern Hebei are quantified by aiming at the understanding of the sources of the severe haze pollution in this region, and the results are compared with December 2007, the haziest month in the period 2001-2010. Model evaluation against meteorological and air quality observations indicates an overall acceptable performance and the model tends to underpredict PM 2.5 and coarse particulate matter (PM 10 ) concentrations during the extremely polluted episodes. The MEIC inventory is proven to be a good estimation in terms of total emissions of cities but uncertainties exist in the spatial allocations of emissions into fine grid resolutions within cities. The source apportionment shows that emissions from northern Hebei and the Beijing-Tianjin city cluster are two major regional contributors to the pollution in January 2013 in Shijiazhuang, compared with those from Shanxi and northern Hebei for December 2007. For Xingtai and Handan, the emissions from northern Hebei and Henan are important. The industrial and domestic sources are the most significant local contributors, and the domestic and agricultural emissions from Shandong and Henan are non-negligible regional sources, especially for Xingtai and Handan. Even in the top two haziest months (i.e., January 2013 and December 2007), a large fraction of PM 2.5 in the three cities may originate from quite different regional sources. These results indicate the importance of establishing a regional joint framework of policymaking and action system to effectively mitigate air pollution in this area, not only over the Beijing-Tianjin-Hebei area, but also surrounding provinces such as Henan, Shandong, and Shanxi.

Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution source

“…A number of studies apply nested simulations with a horizontal resolution in the innermost domain of 12 km (30) or 9 km (31). Wang et al (30) compared domainwide PM 2.5 predictions at 36-km and 12-km grid resolutions, and found that the use of a finer grid changed PM 2.5 performance from a slight underprediction to a moderate overprediction. In our study, the 36-km resolution achieved better model performance than the 12-km resolution.…”

Effectiveness evaluation of temporary emission control action in 2016 in winter in Shijiazhuang, China

“…Trajectory cluster 5 mainly originated from Ningxia Province and passed over Shaanxi, Shanxi, and Hebei before arriving at Shijiazhuang, accounting for 10.8 % of the total trajectories, showing the features of small-scale, short-distance air mass transport and significantly elevated levels of PM 10 (451 µg m −3 ), PM 2.5 (303 µg m −3 ), SO 2 (83 µg m −3 ), NO 2 (104 µg m −3 ), and CO (4.8 mg m −3 ) with trajectory cluster 5 possibly associated with the sources and accumulation of pollutants from surrounding areas. As it is well known that the Beijing-Tianjin-Hebei region is one of the most severely polluted areas in China (Gu et al, 2011;Zhao et al, 2012;Chen et al, 2013;Bi et al, 2014;Wang et al, 2014), it might be an important reason why the concentrations of atmospheric pollutants were higher with trajectory clusters 1 and 5 (Fig. 11 and Table 2).…”

Towards validation of ammonia (NH<sub>3</sub>) measurements from the IASI satellite

“…Looking at interannual variability, for example in 2013, the fertilization peaks of March, July and October are clearly observed . It is interesting to note that the highest January surface concentration (5.1 µg m −3 ) and satellite total column (7.8 ×10 15 molec cm −2 ) are measured during the severe winter pollution episode of 2013 (see Boynard et al, 2014;Wang et al, 2014). The correlation analysis for the monthly values of the 43 NNDMN sites gives a Pearson's r equal to 0.39 (considering the IASI data with a monthly relative retrieval error below 100 %) and a slope of the regression equal to 0.21 (n = 1149).…”