title: Numerical study of the effects of local atmospheric circulations on a pollution event over Beijing-Tianjin-Hebei, China.
abstract: Currently, the Chinese central government is considering plans to build a trilateral economic sphere in the Bohai Bay area, including Beijing, Tianjin and Hebei (BTH), where haze pollution frequently occurs. To achieve sustainable development, it is necessary to understand the physical mechanism of the haze pollution there. Therefore, the pollutant transport mechanisms of a haze event over the BTH region from 23 to 24 September 2011 were studied using the Weather Research and Forecasting model and the FLEXible-PARTicle dispersion model to understand the effects of the local atmospheric circulations and atmospheric boundary layer structure. Results suggested that the penetration by sea-breeze could strengthen the vertical dispersion by lifting up the planetary boundary layer height (PBLH) and carry the local pollutants to the downstream areas; in the early night, two elevated pollution layers (EPLs) may be generated over the mountain areas: the pollutants in the upper EPL at the altitude of 2-2.5 km were favored to disperse by long-range transport, while the lower EPL at the altitude of 1 km may serve as a reservoir, and the pollutants there could be transported downward and contribute to the surface air pollution. The intensity of the sea-land and mountain-valley breeze circulations played an important role in the vertical transport and distribution of pollutants. It was also found that the diurnal evolution of the PBLH is important for the vertical dispersion of the pollutants, which is strongly affected by the local atmospheric circulations and the distribution of urban areas.
authors: Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China.
authors: Yucong
authors: Y
authors: Miao
authors: Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China. Electronic address: lshuhua@pku.edu.cn.
authors: Shuhua
authors: S
authors: Liu
authors: Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China.
authors: Yijia
authors: Y
authors: Zheng
authors: Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China.
authors: Shu
authors: S
authors: Wang
authors: Department of Meteorology, The Pennsylvania State University, University Park, PA 16802, USA.
authors: Bicheng
authors: B
authors: Chen
authors: Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China; Key Laboratory of Regional Climate-Environment Research for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
authors: Hui
authors: H
authors: Zheng
authors: Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China; Department of Atmospheric Sciences, Yunnan University, Kunming 650091, China.
authors: Jingchuan
authors: J
authors: Zhao
mesh_terms: D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D002681:China; D002947:Cities; D004784:Environmental Monitoring; D008962:Models, Theoretical
chemical_list: D000393:Air Pollutants
keywords: Air pollution; FLEXPART model; Mountain–valley breeze circulation; Sea–land breeze circulation; WRF model