OMI formaldehyde column constrained emissions of reactive volatile organic compounds over the Pearl River Delta region of China

Jialin Li; Meigen Zhang; Jinhua Tao; Xiao Han; Yongfu Xu

doi:10.1016/j.scitotenv.2022.154121

OMI formaldehyde column constrained emissions of reactive volatile organic compounds over the Pearl River Delta region of China

Sci Total Environ. 2022 Jun 20:826:154121. doi: 10.1016/j.scitotenv.2022.154121. Epub 2022 Feb 24.

Authors

Jialin Li¹, Meigen Zhang², Jinhua Tao³, Xiao Han⁴, Yongfu Xu⁴

Affiliations

¹ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
² State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: mgzhang@mail.iap.ac.cn.
³ State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China.
⁴ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 35219654
DOI: 10.1016/j.scitotenv.2022.154121

Abstract

In recent years, surface ozone (O₃) concentration was high and became the primary air pollutant in the Pearl River Delta (PRD) region. However, as precursors of tropospheric O₃, the emissions of reactive nonmethane volatile organic compounds (NMVOCs) were reported to have large uncertainties. Here, combined with the simulated formaldehyde (HCHO) columns from the RAMS-CMAQ modeling system, formaldehyde (HCHO) columns derived from the Ozone Monitoring Instrument (OMI) were used as the constraints to improve the emission estimates of the reactive NMVOCs through the linear regression method over the PRD region in March of 2017. The observed highest HCHO concentration was 2-4 times as high as the original simulated results over the PRD region mostly due to the underestimation in the reactive NMVOC emissions, especially the anthropogenic sources. With the regression coefficients calculated through five sensitivity simulation cases as well as the observed HCHO column, the better quantified emissions of reactive NMVOCs were obtained over the PRD region. It showed that the total emissions of reactive NMVOCs were improved by a factor of 2.1. The emissions derived from anthropogenic, biomass burning and biogenic sources increased from 0.0329, 4.69 × 10^-4 and 0.0524 Tg/month to 0.0959, 0.0215 and 0.0620 Tg/month, respectively. As a result, the difference between the observed and modeled high HCHO column decreased to 1-2.5 times, which may be dominated by the enhanced reactive NMVOC emissions derived from anthropogenic sources. Besides, the great improvement in the emissions of reactive NMVOCs contributed to an increase of 20-40 μg/m³ in the maximum daily 8-h average (MDA8) O₃ concentration over the PRD region.

Keywords: Formaldehyde; OMI; RAMS-CMAQ; The Pearl River Delta; Volatile organic compounds.

MeSH terms

Air Pollutants* / analysis
Animals
China
Environmental Monitoring / methods
Formaldehyde / analysis
Male
Ozone* / analysis
Sheep
Volatile Organic Compounds* / analysis

Substances

Air Pollutants
Volatile Organic Compounds
Formaldehyde
Ozone