A significant mechanism of stratospheric O3 intrusion to atmospheric environment: a case study of North China Plain.

Autor: Yuehan Luo, Tianliang Zhao, Kai Meng, Jun Hu, Qingjian Yang, Yongqing Bai, Kai Yang, Weikang Fu, Chenghao Tan, Yifan Zhang, Yanzhe Zhang, Zhikuan Li
Zdroj: Atmospheric Chemistry & Physics Discussions; 2/28/2024, p1-21, 21p
Abstrakt: Stratosphere-to-troposphere transport results in the stratospheric intrusion (SI) of O3 into the free troposphere through the tropopause folding. However, the mechanism of SI influencing the atmospheric environment with the cross-layer transport of O3 from the stratosphere, free troposphere to the atmospheric boundary layer has not been elucidated thoroughly. In this study, a SI event over the North China Plain (NCP) was taken to investigate the mechanism of the cross-layer transport of stratospheric O3 with the impact on the near-surface O3 based on the multi-source reanalysis and observation data and air quality modeling. The results revealed a significant mechanism of stratospheric O3 intrusion to the atmospheric environment induced by an extratropical cyclone system. The SI with downward transport of stratospheric O3 to near-surface layer was driven by the extratropical cyclone system with vertical coupling of "upper westerly trough-middle the Northeast Cold Vortex (NECV)-lower extratropical cyclone" in the troposphere. The deep trough in the westerly jet aroused the tropopause folding, and the lower stratospheric O3 penetrated the folded tropopause into the upper and middle troposphere; the westerly trough was cut off to form a typical cold vortex in the upper and middle troposphere. The compensating downdrafts of the NECV pushed the further downward transport of stratospheric O3 in the free troposphere; The NECV activated an extratropical cyclone in the lower troposphere, and the vertical cyclonic circulation governed the stratospheric O3 from the free troposphere across the boundary layer top invading the near-surface atmosphere. In this SI event, the averaged contribution of stratospheric O3 to near-surface O3 was accounted for 26.77%. The proposed meteorological mechanism of vertical transport of stratospheric O3 into the near-surface atmosphere driven by an extratropical cyclone system could improve the understanding of the influence of stratospheric O3 on atmospheric environment with implications for the coordinated control of atmospheric pollution. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index