This work analyzes and discusses the influence of human activities on the meteorological conditions related to winter haze events in Beijing, Tianjin, and Hebei (i.e., the Jing–Jin–Ji region) during 1961–2016, using the results of two numerical simulation experiments based on the Community Atmosphere Model version 5.1.1 (http://www.cesm.ucar.edu/models/cesm1.0/cam/docs/ug5_1_1/book1.html) used in the international Climate Variability and Predictability Programme (CLIVAR) Climate of the 20th Century. Detection and Attribution Project (C20C+ D&A). The results show that, under the influence of human activities, the changes in dynamical and thermal meteorological conditions related to winter haze events in the Jing–Jin–Ji region are conducive to the formation and accumulation of haze, and prevent the diffusion of pollutants. The dynamical conditions mainly include the obvious weakening of the East Asian winter monsoon (EAWM) and the enhancement of the near-surface anomalous southerly wind. The thermal conditions include the obvious increase in surface temperature, and the enhancement of water vapor transport and near-surface inversion. The relative contribution of dynamical and thermal conditions to the variation of haze days in the Jing–Jin–Ji region is analyzed using statistical methods. The results show that the contribution of human activities to the increase of haze days in the Jing–Jin–Ji region is greater than that of natural forcing for the study period. To be specific, the dynamical meteorological factors contribute more to the haze days than the thermal meteorological factors. The contribution of thermal meteorological factors is basically the same in both scenarios.

本文利用两次数值模拟实验的结果，分析讨论了1961-2016年人类活动对京津冀（即京津冀地区）冬季雾霾事件相关气象条件的影响。基于国际气候变率和可预测性计划 (CLIVAR) 中使用的社区大气模型版本 5.1.1 (http://www.cesm.ucar.edu/models/cesm1.0/cam/docs/ug5_1_1/book1.html) ) 20 世纪的气候。检测和归因项目（C20C+ D&A）。结果表明，在人类活动的影响下，京津冀地区与冬季雾霾事件相关的动力和热气象条件的变化有利于雾霾的形成和积累，阻止污染物的扩散。动力条件主要包括东亚冬季风（EAWM）明显减弱和近地表异常偏南风增强。热条件包括地表温度明显升高、水汽输送增强和近地表逆温。使用统计方法分析了动力和热条件对京津冀地区雾霾天数变化的相对贡献。结果表明，在研究期间，人类活动对京津冀地区雾霾日数增加的贡献大于自然强迫。具体而言，动力气象因素对雾霾天数的贡献大于热气象因素。