Tracing the origins of stratospheric ozone intrusions: direct vs. indirect pathways and their impacts on Central and Eastern China in spring–summer 2019

作者：Kai Meng, Tianliang Zhao, Yongqing Bai, Ming C. Wu, Le Cao, Xuewei Hou, Yuehan Luo, Yongcheng Jiang · 发表于：Atmospheric chemistry and physics · 年份：2024 · DOI：10.5194/acp-24-12623-2024 · 被引用次数：14 · 研究领域：Atmospheric Ozone and Climate、Atmospheric chemistry and aerosols、Atmospheric and Environmental Gas Dynamics

Abstract. The impact of stratospheric intrusions (SIs) on Central and Eastern China (CEC) with severe ozone pollution presents a range of uncertainties, underscoring the imperative for sustained research endeavors. In this study, we propose a traceability assessment method that can derive high-resolution critical source areas (CSAs) of SIs by utilizing ambient air quality observations, global ozone (re)analysis data, and customized Lagrangian simulations. This approach enables us to facilitate a meticulous and systematic examination of the impact of direct and indirect SIs on tropospheric and near-surface ozone in six important sub-regions within the CEC during the spring and summer of 2019, as well as the unique circulations driving SIs, from a more refined and targeted tracing perspective. The findings reveal that impacts of indirect intrusions are more efficient at monthly scales, with contributions to tropospheric ozone reaching up to twice the magnitude of direct intrusions. The impacts of direct intrusions are more pronounced at daily scales, primarily occurring in May. In terms of contribution to near-surface ozone, the eastern plains frequently witness ozone exceedance events, with the most substantial impact from SIs observed (e.g., contributing 15.8 % and 16.7 % to near-surface ozone in North China and East China, respectively), showcasing a remarkable ability to capture descending lower-stratospheric air. In contrast, the Loess Plateau and Central China, situated i...