Why does surface ozone peak before a typhoon landing in southeast China?
oleh: Y. C. Jiang, T. L. Zhao, J. Liu, X. D. Xu, C. H. Tan, X. H. Cheng, X. Y. Bi, J. B. Gan, J. F. You, S. Z. Zhao
| Format: | Article |
|---|---|
| Diterbitkan: | Copernicus Publications 2015-12-01 |
Deskripsi
A high O<sub>3</sub> episode with the large increases in surface ozone by 21–42 ppbv and the nocturnal surface O<sub>3</sub> levels exceeding 70 ppbv was observed in the region between Xiamen and Quanzhou over the southeastern coast of China during 12–14 June 2014, before the Typhoon Hagibis landing. Variations in the surface O<sub>3</sub>, NO<sub>2</sub>, CO and meteorology during the Typhoon Hagibis event clearly suggest a substantial impact of the peripheral downdrafts in the large-scale typhoon circulation on such an O<sub>3</sub> episode excluding the contributions of photochemical production and the horizontal transport. The influence of vertical O<sub>3</sub> transport from the upper troposphere and lower stratosphere (UTLS) region on high surface O<sub>3</sub> levels is further confirmed by a negative correlation between surface O<sub>3</sub> and CO concentrations as well as dry surface air observed during the O<sub>3</sub> episode. This study provides observational evidence of typhoon-driven intrusion of O<sub>3</sub> from the UTLS region to surface air, revealing a significant effect of such a process of stratosphere–troposphere exchange (STE) of O<sub>3</sub> on tropospheric O<sub>3</sub> and ambient air quality.