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首页> 外文期刊>Atmospheric chemistry and physics >Exploring the severe winter haze in Beijing: the impact of synoptic weather, regional transport and heterogeneous reactions
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Exploring the severe winter haze in Beijing: the impact of synoptic weather, regional transport and heterogeneous reactions

机译：探索北京严冬的阴霾：天气天气，区域运输和异质反应的影响

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Extreme haze episodes repeatedly shrouded Beijing during the winter of2012–2013, causing major environmental and health problems. To betterunderstand these extreme events, we performed a model-assisted analysis ofthe hourly observation data of PM2.5 and its major chemicalcompositions. The synthetic analysis shows that (1) the severe winter hazewas driven by stable synoptic meteorological conditions over northeasternChina, and not by an abrupt increase in anthropogenic emissions. (2)Secondary species, including organics, sulfate, nitrate, and ammonium, werethe major constituents of PM2.5 during this period. (3) Due to thedimming effect of high loading of aerosol particles, gaseous oxidantconcentrations decreased significantly, suggesting a reduced production ofsecondary aerosols through gas-phase reactions. Surprisingly, theobservational data reveals an enhanced production rate of secondaryaerosols, suggesting an important contribution from other formationpathways, most likely heterogeneous reactions. These reactions appeared tobe more efficient in producing secondary inorganics aerosols than organicaerosols resulting in a strongly elevated fraction of inorganics duringheavily polluted periods. (4) Moreover, we found that high aerosolconcentration was a regional phenomenon. The accumulation process of aerosolparticles occurred successively from cities southeast of Beijing. Theapparent sharp increase in PM2.5 concentration of up to several hundredμg m?3 per hour recorded in Beijing represented rapid recoveryfrom an interruption to the continuous pollution accumulation over theregion, rather than purely local chemical production. This suggests thatregional transport of pollutants played an important role during thesesevere pollution events.
机译：2012-2013年冬季，极端的霾霾事件屡次笼罩北京，造成重大的环境和健康问题。为了更好地理解这些极端事件，我们对PM 2.5 及其主要化学成分的每小时观测数据进行了模型辅助分析。综合分析表明：（1）严峻的冬季霾是由东北地区稳定的天气气象条件驱动的，而不是人为排放量的突然增加。 （2）有机物，硫酸盐，硝酸盐和铵盐等次生物种是该时期PM 2.5 的主要成分。 （3）由于高浓度气溶胶颗粒的调光作用，气态氧化剂浓度显着降低，这表明通过气相反应减少了次级气溶胶的产生。令人惊讶的是，观测数据揭示了次级气溶胶的生产率提高，表明其他形成途径（最可能是异质反应）的重要贡献。这些反应似乎在产生次要无机气溶胶方面比有机气溶胶更有效，从而导致在严重污染期间无机组分的含量大大增加。 （4）此外，我们发现高浓度的气溶胶是区域现象。气溶胶颗粒的积累过程是从北京东南部城市开始的。北京记录到的PM 2.5 浓度明显每小时最高可达几百微克m ？3 的急剧增加代表了该区域从中断到连续的污染积累的快速恢复，而不是纯粹的当地化学生产。这表明在这些严重的污染事件中，污染物的区域运输起着重要作用。

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