Estimation of Long-Term Ozone Variability in East Asia (2005–2024): Integration of OMI, TROPOMI, and GEMS Satellite Data

East Asia is a region with particularly high emissions of ozone precursors due to the effects of industrialization and urbanization, making continuous monitoring of air pollution and environmental changes crucial. To address this need, the GEMS sensor onboard the GK-2B satellite, launched in 2020, serves as an important tool for real-time observation of the East Asian region from a geostationary orbit. While GEMS offers the advantage of continuous monitoring of air quality in East Asia, its relatively short observation period limits its use for long-term analysis. To overcome this limitation, this study integrates GEMS, OMI and TROPOMI satellite data to construct a 20-year record (2005–2024) and analyze the seasonal and spatial characteristics of ozone variability. Level 2 data from each satellite were processed using a consistent algorithm to generate Level 3 data, and the discrepancies during overlapping observation periods between the satellites were corrected to reduce inconsistencies. The corrected data were validated through cross-verification between the satellites. The validation results showed a slope ranging from 0.95 to 1, an R-squared value above 0.9, and an RMSE of less than 5 DU. To further assess the accuracy of the long-term data generated in this study, validation with ground-based observations is also necessary.

 

This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (NRF-RS-2023-00219830) and a grant from the National Institute of Environment Research (NIER), funded by the Ministry of Environment (MOE) of the Republic of Korea (NIER-2024-01-02-042).