TY - JOUR
T1 - Roles of photochemical consumption of VOCs on regional background O3 concentration and atmospheric reactivity over the pearl river estuary, Southern China.
AU - Sun, JY
AU - Yu, XY
AU - Ling, ZH
AU - Fang, GZ
AU - Ming, LL
AU - Zhao, J
AU - Zou, SC
AU - Guan, HT
AU - Wang, HC
AU - Wang, XM
AU - Wang, Z
AU - Gao, Y
AU - Tham, YJ
AU - Guo, Hai
AU - Zhang, YL
N1 - Publisher Copyright:
© 2024 Elsevier B.V.
PY - 2024/6/10
Y1 - 2024/6/10
N2 - Understanding of the photochemical ozone (O
3) pollution over the Pearl River Estuary (PRE) of southern China remains limited. We performed an in-depth analysis of volatile organic compounds (VOCs) data collected on an island (i.e., the Da Wan Shan Island, DWS) located at the downwind of Pearl River Delta (PRD) from 26 November to 15 December 2021. Abundances of O
3 and its precursors were measured when the air masses originated from the inland PRD. We observed that the VOCs levels at the DWS site were lower, while the mixing ratio of O
3 was higher, compared to those reported at inland PRD, indicating the occurrence of photochemical consumption of VOCs during the air masses transport, which was further confirmed by the composition and diurnal variations of VOCs, as well as ratios of specific VOCs. The simulation results from a photochemical box model showed that the O
3 level in the outflow air masses of inland PRD (O
3(out-flow)) was the dominant factor leading to the intensification of O
3 pollution and the enhancement of atmospheric radical concentrations (ARC) over PRE, which was mainly contributed by the O
3 production via photochemical consumption of VOCs during air masses transport. Overall, our findings provided direct quantitative evidence for the roles of outflow O
3 and its precursors from inland PRD on O
3 abundance and ARC over the PRE area, highlighting that alleviation of O
3 pollution over PRE should focus on the impact of photochemical loss of VOCs in the outflow air masses from inland PRD.
AB - Understanding of the photochemical ozone (O
3) pollution over the Pearl River Estuary (PRE) of southern China remains limited. We performed an in-depth analysis of volatile organic compounds (VOCs) data collected on an island (i.e., the Da Wan Shan Island, DWS) located at the downwind of Pearl River Delta (PRD) from 26 November to 15 December 2021. Abundances of O
3 and its precursors were measured when the air masses originated from the inland PRD. We observed that the VOCs levels at the DWS site were lower, while the mixing ratio of O
3 was higher, compared to those reported at inland PRD, indicating the occurrence of photochemical consumption of VOCs during the air masses transport, which was further confirmed by the composition and diurnal variations of VOCs, as well as ratios of specific VOCs. The simulation results from a photochemical box model showed that the O
3 level in the outflow air masses of inland PRD (O
3(out-flow)) was the dominant factor leading to the intensification of O
3 pollution and the enhancement of atmospheric radical concentrations (ARC) over PRE, which was mainly contributed by the O
3 production via photochemical consumption of VOCs during air masses transport. Overall, our findings provided direct quantitative evidence for the roles of outflow O
3 and its precursors from inland PRD on O
3 abundance and ARC over the PRE area, highlighting that alleviation of O
3 pollution over PRE should focus on the impact of photochemical loss of VOCs in the outflow air masses from inland PRD.
KW - Atmospheric reactivity
KW - Pearl River Estuary
KW - Regional background O3 concentration
KW - Volatile organic compounds
UR - http://www.scopus.com/inward/record.url?scp=85190827123&partnerID=8YFLogxK
U2 - https://doi.org/ 10.1016/j.scitotenv.2024.172321
DO - https://doi.org/ 10.1016/j.scitotenv.2024.172321
M3 - Journal article
SN - 0048-9697
VL - 928
JO - Science of the Total Environment
JF - Science of the Total Environment
IS - 172321
M1 - 172321
ER -