Limitation of O3 Dry Deposition by Elevated-Source NO Emissions and Surface Dryness in Urban Environments.
5 affiliations
- 1The Robert H. Smith Faculty of Agriculture, Food and Environment, Department of Soil and Water Sciences, The Hebrew University of Jerusalem, Rehovot7610001, Israel.
- 2College of Environment and Climate, Institute for Environmental and Climate Research, Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Jinan University, Guangzhou511443, China.
- 3Department of Computer Science, Jerusalem College of Technology, Jerusalem91160, Israel.
- 4School of Ecology and Environment, Hainan University, Haikou, Hainan Province570228, China.
- 5Department of Atmospheric Sciences, Yunnan University, Kunming650500, China.
Abstract
Tropospheric ozone (O3) is a major air pollutant that adversely affects human health, climate and ecosystems. However, its removal in urban environments remains poorly represented in air-quality and climate models, largely due to limited flux-based observations of urban O3 deposition. Using eddy-covariance flux measurements from a meteorological tower in Beijing, we show─for the first time to our knowledge─that surface uptake plays a central role in O3 removal in urban environments but is strongly limited under dry conditions by evaporation and by higher-above-measurement nitrogen monoxide (NO) concentrations (HAMNC), inferred from downward NO fluxes and likely linked to elevated-source NO emissions. These limitations led to significantly more frequent positive ozone-flux events under low relative humidity (RH < 30%) and downward NO flux, reducing downward O3 flux by ∼5% and ∼3%, respectively. We provide explicit functional relationships describing the response of downward O3 velocity (Vdw,O3) to both near-surface dryness (RH) and HAMNC, accounting for processes missed by routine ground-based measurements that can lead to misinterpretation of O3 removal in the urban environment and beyond. Incorporating the RH-dependent limitation of Vdw,O3 into air-quality and climate models is critical, given that ∼40% of the global land surface is arid or semiarid.
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BibTeX
@article{choi2026limitation,
title = {{Limitation of O3 Dry Deposition by Elevated-Source NO Emissions and Surface Dryness in Urban Environments.}},
author = {Daniel Choi and Yibo Huangfu and Erick Fredj and Qian Li and Bin Yuan and Xiaoxiao Zhang and Xianjun He and Huizhi Liu and Eran Tas},
journal = {Environmental science \& technology},
year = {2026},
month = oct,
doi = {10.1021/acs.est.6c05093},
url = {https://europepmc.org/article/MED/42917002},
note = {CC BY},
}
RIS
TY - JOUR
TI - Limitation of O3 Dry Deposition by Elevated-Source NO Emissions and Surface Dryness in Urban Environments.
AU - Daniel Choi
AU - Yibo Huangfu
AU - Erick Fredj
AU - Qian Li
AU - Bin Yuan
AU - Xiaoxiao Zhang
AU - Xianjun He
AU - Huizhi Liu
AU - Eran Tas
PY - 2026
DA - 2026/10/01
JO - Environmental science & technology
DO - 10.1021/acs.est.6c05093
UR - https://europepmc.org/article/MED/42917002
AB - Tropospheric ozone (O3) is a major air pollutant that adversely affects human health, climate and ecosystems. However, its removal in urban environments remains poorly represented in air-quality and climate models, largely due to limited flux-based observations of urban O3 deposition. Using eddy-covariance flux measurements from a meteorological tower in Beijing, we show─for the first time to our knowledge─that surface uptake plays a central role in O3 removal in urban environments but is strongly limited under dry conditions by evaporation and by higher-above-measurement nitrogen monoxide (NO) concentrations (HAMNC), inferred from downward NO fluxes and likely linked to elevated-source NO emissions. These limitations led to significantly more frequent positive ozone-flux events under low relative humidity (RH < 30%) and downward NO flux, reducing downward O3 flux by ∼5% and ∼3%, respectively. We provide explicit functional relationships describing the response of downward O3 velocity (Vdw,O3) to both near-surface dryness (RH) and HAMNC, accounting for processes missed by routine ground-based measurements that can lead to misinterpretation of O3 removal in the urban environment and beyond. Incorporating the RH-dependent limitation of Vdw,O3 into air-quality and climate models is critical, given that ∼40% of the global land surface is arid or semiarid.
SN - 0013-936X
SN - 1520-5851
ER -