To understand the transport patterns and major sources of ozone (O₃) in Nanjing, this study carried out the 48-hour backward trajectories of air masses in Nanjing from March 2021 to March 2022, based on the HYSPLIT backward trajectory model driven by GDAS global reanalysis data. The primary transmission routes and putative source locations of O₃ pollution in Nanjing were determined through the integration of trajectory clustering analysis, potential source contribution function (PSCF), and concentration-weighted trajectory (CWT) analysis with meteorological data and O₃ concentration data. The results showed that the high O₃ concentrations and exceedance rates in Nanjing were in late spring and early summer, with the highest in June. The diurnal variation of O₃ concentrations in all seasons exhibited a single peak with a maximum from 13:00 to 16:00. The southeasterly flow passing through Zhenjiang, Changzhou, Wuxi, Suzhou, and Shanghai dominated the O₃ pollution in Nanjing. The PSCF and CWT presented a high consistency of O₃ potential sources in Nanjing. Zhenjiang, Ma’anshan, Changzhou, Wuxi, Suzhou, and Huzhou were identified as the main potential source regions of O₃ pollution in Nanjing. This study provides accurate theoretical references for regional joint prevention and control of O₃ pollution in Nanjing.

中文翻译：

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南京市O3变化研究及周边源分析

为了解南京地区臭氧（O 3 ）的输送模式和主要来源，本研究基于GDAS全球驱动的HYSPLIT后向轨迹模型，对2021年3月至2022年3月南京地区气团48小时后向轨迹进行了_研究。重新分析数据。通过轨迹聚类分析、潜在源贡献函数（PSCF）和浓度加权轨迹（CWT）分析与气象数据和O 3 浓度数据相结合，确定了南京市O 3 污染的主要传播路径和_推定源_位置。结果表明，南京地区O ₃浓度和超标率较高的时段是春末夏初，其中6月份最高。各季节O ₃浓度日变化均呈现单峰，最大值出现在13:00～16:00。南京市O ₃污染以流经镇江、常州、无锡、苏州、上海的东南气流为主。PSCF和CWT呈现出南京地区O _{3潜在来源的高度一致性。}镇江、马鞍山、常州、无锡、苏州、湖州被确定为南京市O _{3污染的主要潜在源区。}该研究为南京市O ₃污染区域联防联控提供准确的理论参考。