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

Abstract

Abstract. Extremely severe and persistent haze occurred in January 2013 over the eastern and northern China. The record-breaking high concentrations of fine particulate matter (PM2.5) 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, seven of the top ten polluted cities in China were within 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 year of 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 the northern China at horizontal grid resolutions of 36 and 12 km, respectively, using the Multi-resolution Emission Inventory of China (MEIC). The source contributions of major source regions and sectors to PM2.5 concentrations in the three most-polluted cities in southern Hebei are quantified 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 2001–2010. Model evaluation against meteorological and air quality observations indicates an overall acceptable performance and the model tends to underpredict PM2.5 and coarse particulate matter (PM10) concentrations during the extremely severe polluted episodes. The MEIC inventory is proved 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 the northern Hebei and the Beijing–Tianjin city cluster are two major regional contributors to the pollution in January 2013 in Shijiazhuang, comparing with those from Shanxi and the northern Hebei for December 2007. For Xingtai and Handan, the emissions from the 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 unnegligible 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 PM2.5 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 Beijing–Tianjin–Hebei area, but also surrounding provinces such as Henan, Shandong, and Shanxi.

The Aerosol-Radiation Interaction Effects of Different Particulate Matter Components during Heavy Pollution Periods in China

“…The high uncertainty of emission inventories and meteorological simulation results affected the accuracy of the air pollution simulation results. A previous study also showed a large bias during heavily polluted days, which is an inherent characteristic that the model can produce [39]. According to the U.S. Environmental Protection Agency [38], all parameters followed the guidelines, and the WRF-Chem model predicted variables reasonably well in this work.…”

Satellite and Ground Observations of Severe Air Pollution Episodes in the Winter of 2013 in Beijing, China

“…Besides our direct visualization, model simulations also supported regional transport as a significant resource of smog episodes. In this study, however, the ground monitor data collected from the same source of our study was only used for evaluating of the simulation results of Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality (CMAQ) modeling system applied in East Asia and the northern China with the Multi-resolution Emission Inventory of China (MEIC) (Wang et al, 2013a).…”

“…Another simulation study suggested that these severe PM 2.5 episodes were driven by stable synoptic weather conditions rather than abrupt increase in anthropogenic emissions. Another modelling study over Hebei province found that external contributions of PM 2.5 in three heavily polluted cities may have originated from different areas, emphasizing the importance to establish a regional emission control framework (Wang et al, 2013a). However, none of these studies were designed to accurately estimate PM 2.5 concentration during this event.…”

Enhanced sulfate formation during China's severe winter haze episode in January 2013 missing from current models

“…The Group B cities are located in the most polluted city cluster, and emissions from this region are underestimated in the model. Similar to the GEOS‐Chem model, the regional‐scale Community Multi‐scale Air Quality model was found unable to reproduce the high PM 2.5 concentrations over Group B cities [ Wang et al ., ].…”