ChinaHighSO₂: Daily Seamless 1 km Ground-Level SO₂ Dataset for China (2019–Present)

ChinaHighSO2 is part of a series of long-term, seamless, high-resolution, and high-quality datasets of air pollutants for China (i.e., ChinaHighAirPollutants, CHAP). It is generated from big data sources (e.g., ground-based measurements, satellite remote sensing products, atmospheric reanalysis, and model simulations) using artificial intelligence, taking into account the spatiotemporal heterogeneity of air pollution. Here is the big data-derived seamless (spatial coverage = 100%) daily, monthly, and yearly 1 km (i.e., D1K, M1K, and Y1K) ground-level SO2 dataset for China from 2019 to the present. This dataset exhibits high quality, with a cross-validation coefficient of determination (CV-R2) of 0.79, a root-mean-square error (RMSE) of 3.93 µg m-3, and a mean absolute error (MAE) of 2.06 µg m-3 on a daily basis. If you use the ChinaHighSO2 dataset in your scientific research, please cite the following references (Wei et al., ACP, 2023; Yang et al., 2026): Wei, J., Li, Z., Wang, J., Li, C., Gupta, P., and Cribb, M. Ground-level gaseous pollutants (NO2, SO2, and CO) in China: daily seamless mapping and spatiotemporal variations. Atmospheric Chemistry and Physics, 2023, 23, 1511–1532. https://doi.org/10.5194/acp-23-1511-2023 Yang, Z., Cheng, F., Gao, J., Liu, H., and Wei, J. Satellite observations reveal heterogeneous atmospheric composition responses to rapid emission changes. Atmospheric Chemistry and Physics, 2026, 26, 7933–7947. https://doi.org/10.5194/acp-26-7933-2026 Note that the ChinaHighSO2 dataset is also available for periods prior to 2019, but at a spatial resolution of 10 km: all (including daily) data for the years 2013–2018 are accessible at: https://doi.org/10.5281/zenodo.4641538 More CHAP datasets for different air pollutants are available at: https://weijing-rs.github.io/product.html