Spatiotemporal variations of ozone and associated human health risks during tropical cyclones in China

Abstract Surface ozone pollution poses serious health risks worldwide while individual tropical cyclone (TC) can affect surface ozone through air transport and changes in meteorology influencing ozone formation. However, general variations in surface ozone under the influence of all TCs, as well as the corresponding health risks remain unclear. Using a High-resolution Air Quality Reanalysis Dataset over China (CAQRA), this study examines spatial-temporal variations of ozone and associated health risks during TC events from 2013 to 2019. Results show three distinct regional responses. In eastern coastal China, ozone decreases and reaches its minimum at the moment nearest to the TC center (0 h), due to strong winds and moist inflow. In southeastern and northeastern China, ozone rises slightly and then declines to its minimum about 34 h after 0 h, likely resulting from the changes of temperature and relative humidity (RH) and a lagging effect of strong winds. In central and southwestern China, ozone increases due to the high temperature and low RH near the peripheral circulation of TCs. Health impact assessments indicate the highest ozone-related risks concentrate in the eastern and southern China. These findings highlight the importance of incorporating the air pollution impacts induced by TCs into public health risk assessments.