Why does surface ozone peak before a typhoon landing in southeast China?
- 1Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
- 2School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
- 3Department of Geography and Planning, University of Toronto, Toronto, M5S 3G3, Canada
- 4State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
- 5Institute of Atmospheric Composition, Key Laboratory of Atmospheric Chemistry of China Meteorological Administration, Chinese Academy of Meteorological Sciences, Beijing 100081, China
- 6State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
- 7Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510080, China
- 8Fujian Provincial Environmental Monitoring Center, Fuzhou 350003, China
- 9Quanzhou Municipal Bureau of Meteorology, Quanzhou 361012, China
- 10Xiamen Municipal Bureau of Meteorology, Xiamen 362000, China
Abstract. A high O3 episode with the large increases in surface ozone by 21–42 ppbv and the nocturnal surface O3 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 O3, NO2, 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 O3 episode excluding the contributions of photochemical production and the horizontal transport. The influence of vertical O3 transport from the upper troposphere and lower stratosphere (UTLS) region on high surface O3 levels is further confirmed by a negative correlation between surface O3 and CO concentrations as well as dry surface air observed during the O3 episode. This study provides observational evidence of typhoon-driven intrusion of O3 from the UTLS region to surface air, revealing a significant effect of such a process of stratosphere–troposphere exchange (STE) of O3 on tropospheric O3 and ambient air quality.