Turbulence barrier effect during heavy haze pollution events

Yan Ren; Hongsheng Zhang; Xiaoye Zhang; Wei Wei; Qianhui Li; Bingui Wu; Xuhui Cai; Yu Song; Ling Kang; Tong Zhu

doi:10.1016/j.scitotenv.2020.142286

Turbulence barrier effect during heavy haze pollution events

Sci Total Environ. 2021 Jan 20:753:142286. doi: 10.1016/j.scitotenv.2020.142286. Epub 2020 Sep 8.

Authors

Yan Ren¹, Hongsheng Zhang², Xiaoye Zhang³, Wei Wei⁴, Qianhui Li¹, Bingui Wu⁵, Xuhui Cai⁶, Yu Song⁷, Ling Kang⁷, Tong Zhu⁷

Affiliations

¹ Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100081, PR China.
² Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100081, PR China. Electronic address: hsdq@pku.edu.cn.
³ State Key Laboratory of Severe Weather and Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, China Meteorological Administration (CMA), Beijing 100081, PR China. Electronic address: xiaoye@cma.gov.cn.
⁴ State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, China Meteorological Administration (CMA), Beijing 100081, PR China.
⁵ Tianjin Municipal Meteorological Bureau, Tianjin 300074, PR China.
⁶ State Key Joint Laboratory of Environmental Simulation and Pollution Control, Department of Environmental Science, Peking University, Beijing 100081, PR China. Electronic address: xhcai@pku.edu.cn.
⁷ State Key Joint Laboratory of Environmental Simulation and Pollution Control, Department of Environmental Science, Peking University, Beijing 100081, PR China.

PMID: 33207486
DOI: 10.1016/j.scitotenv.2020.142286

Abstract

Under low wind speed conditions, the frequent intermittent turbulence phenomenon in the atmospheric boundary layer (ABL) greatly weakens the turbulent diffusion of pollutants to cause the heavy haze events. Turbulence may disappear at certain heights forming a laminar flow as if there is a barrier layer hindering the transmission up and down during the heavy haze periods. The turbulent data at five layers and PM_2.5 (fine particular matter with a diameter smaller than 2.5 μm) concentration at two levels were used to discuss the barrier that is called the barrier effect vividly. The results revealed that the changes in the PM_2.5 concentration at different heights corresponded excellently with the change in vertical turbulence barrier effect. This work explains the physical mechanism responsible for the accumulation of pollutants in heavy pollution events and the influence of turbulent diffusion conditions on the distribution of the PM_2.5 concentration.

Keywords: Atmospheric boundary layer; Barrier effect; Haze; Turbulent diffusion.