Drivers of the rapid rise and daily-based accumulation in PM1

Junting Zhong; Xiaoye Zhang; Yangmei Zhang; Yaqiang Wang; Zhouxiang Zhang; Xiaojing Shen; Junying Sun; Lei Zhang; Ke Gui; Sanxue Ren; Huarong Zhao; Yubin Li; Zhiqiu Gao

doi:10.1016/j.scitotenv.2020.143394

Drivers of the rapid rise and daily-based accumulation in PM₁

Sci Total Environ. 2021 Mar 15:760:143394. doi: 10.1016/j.scitotenv.2020.143394. Epub 2020 Nov 5.

Authors

Junting Zhong¹, Xiaoye Zhang², Yangmei Zhang³, Yaqiang Wang⁴, Zhouxiang Zhang⁵, Xiaojing Shen⁴, Junying Sun⁴, Lei Zhang⁴, Ke Gui⁴, Sanxue Ren⁴, Huarong Zhao⁴, Yubin Li⁶, Zhiqiu Gao⁷

Affiliations

¹ State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing 100081, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing 100081, China; Center for Excellence in Regional Atmospheric Environment, IUE, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: xiaoye@cma.gov.cn.
³ State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing 100081, China. Electronic address: ymzhang@cma.gov.cn.
⁴ State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry of CMA, Chinese Academy of Meteorological Sciences, Beijing 100081, China.
⁵ Hubei Ecological Environment Monitoring Center Station, Wuhan 430070, China.
⁶ Nanjing University of Information Science & Technology, Nanjing 210044, China.
⁷ Nanjing University of Information Science & Technology, Nanjing 210044, China; Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.

PMID: 33221018
DOI: 10.1016/j.scitotenv.2020.143394

Abstract

Submicron particle matter (PM₁) that rapidly reaches exceedingly high levels in several or more hours in the North China Plain (NCP) has been threating~400 million individuals' health for decades. The precise cause of the rapid rise in PM₁ remains uncertain. Based on sophisticated measurements in PM₁ characterizations and corresponding boundary-layer (BL) meteorology in the NCP, it demonstrates that this rising is mainly driven by BL meteorological variability. Large increases in near-ground inversions and decreases in vertical heat/momentum fluxes during the day-night transition result in a significant reduction in mixing space. The PM₁ that is vertically distributed before accumulates at the near-ground and then experiences a rapid rise. Besides meteorological variability, a part of the rise in organics is ascribed to an increase of coal combustion at midnight. The daily-based accumulation of PM₁ is attributed to day-to-day vertical meteorological variability, particularly diminishing mixing layer height exacerbated by aerosol-radiation feedback. Resolved by a multiple linear regression model, BL meteorological variability can explain 71% variances of PM₁. In contrast, secondary chemical reactions facilitate the daily-based accumulation of PM₁ rather than the rapid rise. Our results show that BL meteorological variability plays a dominant role in PM₁ rising and day-to-day accumulation, which is crucial for understanding the mechanism of heavy pollution formation.

Keywords: Coal combustion; Daily-based accumulation; Meteorological variability; PM(1) composition; Rapid rise.