Contribution of trans-boundary transport to ozone concentrations revealed by vertical ozone sonde profiles in South Korea

In South Korea, surface ozone concentrations are increasing and high concentrations have also been observed in the upper boundary layer. These elevated ozone levels are known to be affected by trans-boundary transport. Understanding the vertical ozone distribution of ozone is therefore essential for investigating the impact of trans-boundary transport on regional air quality. This study, at first, analyzes ozone sonde data to classify trans-boundary transport cases and, then, examine their impact on the vertical ozone distribution in South Korea. It also identifies ozone formation characteristics under both trans-boundary and local formation scenarios. The ozone sondes were launched at Anmyeon-do site in South Korea, from July 27 to September 2, 2022. The mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, is used to provide meteorological data for photochemical model simulations using the Community Multiscale Air Quality (CMAQ) model. The results indicate that trans-boundary transport increases ozone concentrations mainly at 850 hPa, with remaining significant contributions up to 500 hPa. These results highlight the importances of understanding ozone transport at different altitudes and considering both transboundary and local factors for establishing effective air quality management.

This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment(MOE).
I’d like to thank the Environmental Satellite Center and the Atmospheric Environment Research Division of the National Institute of Environmental Research for providing ozone sonde data.
This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (RS-2023-00219830).