Meteorological Drivers of Summertime Ground-Level Ozone in Jilin City (2020-2023): WRF–CMAQ Simulation and Health Risk Assessment

Abstract

The rising incidence of ground-level ozone (O₃) air pollution and its subsequent adverse health effects in urban areas, particularly in emerging countries such as China, warrant urgent attention. Ground-level O₃ is a major health threat, accelerating respiratory diseases and cardiovascular disorders. Despite widespread studies in major industrial areas, the spatial and temporal patterns of O₃ are, however, insufficient, particularly for smaller cities such as Jilin, North China, with reference to meteorological forcing. The study aims to bridge this gap through an analysis of the spatiotemporal variability of O₃ and related health effects for the period 2020 to 2023 for the summer seasons (May to July) for Jilin City, incorporating both meteorological and air quality models (WRF v4.3.3 and CMAQ v5.4) with inputs from various monitoring stations. The findings reveal that the higher temperatures in 2023 facilitated the production of O₃, whereas changes in the wind pattern and lower planetary boundary layer height influenced the transport of pollutants. The seasonal variations of O₃ were, however, underpredicted for the peak occurrences using the CMAQ model, with a normalised mean bias ranging from −30.98% to −22.98%. The health risk for the period, as indicated by the Normalised Health-based Air Quality Index (NHAQI), showed an improvement, albeit slight, in air quality from 2020 to 2023, accompanied by a decrease in the excess health risk (from 2.19% to 2.13%). The spatial analysis revealed continuous areas of high risk, particularly during stagnation periods in urban areas. The study highlights the importance of localized, season-oriented strategies for mitigating O3 exposure and minimizing harm to public health. However, the marginal air quality improvement for the period 2020–2023 is encouraging, suggesting further improvement is possible. Increased accuracy must be achieved through model improvements, refined emission inventories, and targeted remedies at locations with excessive O₃ levels, particularly sensitive urban locations.