Spatio-temporally differentiated impacts of temperature inversion on surface PM2.5 in eastern China

Min Shao; Xiaoying Xu; Yutong Lu; Qili Dai

doi:10.1016/j.scitotenv.2022.158785

Spatio-temporally differentiated impacts of temperature inversion on surface PM_2.5 in eastern China

Sci Total Environ. 2023 Jan 10:855:158785. doi: 10.1016/j.scitotenv.2022.158785. Epub 2022 Sep 16.

Authors

Min Shao¹, Xiaoying Xu², Yutong Lu³, Qili Dai⁴

Affiliations

¹ School of Environment, Nanjing Normal University, Nanjing 210046, China.
² School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210031, China.
³ School of Atmospheric Sciences, Nanjing University, Nanjing 210046, China.
⁴ State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; China Meteorological Administration-Nankai University (CMA-NKU) Cooperative Laboratory for Atmospheric Environment-Health Research, Tianjin 300350, China. Electronic address: daiql@nankai.edu.cn.

PMID: 36116664
DOI: 10.1016/j.scitotenv.2022.158785

Abstract

Temperature inversion (TI) is one of the meteorological conditions that significantly affect regional air quality. Knowledge gap regarding the impacts of TI on surface PM_2.5 in different topographies still existed. In the present study, the occurrence frequency, temperature lapse rate (TLR), depth, and the diurnal variations of TI, surface-based TI (SBTI), elevated TI (ElTI), and multiple layers of TIs (MultiTI) and their impacts on near-surface PM_2.5 concentrations over eastern China that covers a range of topographies and climates, are systematically investigated based on global reanalysis ERA5 and the nationwide monitoring PM_2.5 dataset from 2014 to 2020. TIs occurred mostly in the early morning. Different types of TIs present distinctive seasonal and spatial patterns. The majority of SBTIs and ElTIs occurred during nighttime in northern China and daytime in southern China, respectively, as the result of their formation mechanisms. SBTIs usually had larger TLR while ElTIs had deeper depth. SBTIs showed strong enhancement effects on PM_2.5 concentration over the study domain while ElTIs showed more obvious impacts on northern nocturnal PM_2.5. The peak time of PM_2.5 was found around 18:00-22:00 LST, and TLR and depth of TIs are thought to be more relevant to PM_2.5 peak concentration due to their coincident peak times. The strength of TIs is therefore more crucial in regulating PM_2.5 than its occurrence frequency. Based on statistical analysis, our study provided a large picture of the generic spatiotemporal patterns of TIs and illustrated the impacts of different TIs on surface PM_2.5 pollution on a diurnal basis. For a deeper understanding of the formation of PM_2.5 pollution, more attention needs to be paid to the nocturnal PM_2.5 not only at surface level but also at higher levels in the presence of TIs.

Keywords: Air pollution; China; Meteorology; PM(2.5); Temperature inversion.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
China
Environmental Monitoring
Particulate Matter / analysis
Seasons
Temperature

Substances

Particulate Matter
Air Pollutants