ChinaHighNO2 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 NO2 dataset for China from 2019 to the present. This dataset exhibits high quality, with a cross-validation coefficient of determination (CV-R2) of 0.93, a root-mean-square error (RMSE) of 4.89 µg m-3, and a mean absolute error (MAE) of 3.48 µg m-3 on a daily basis. If you use the ChinaHighNO2 dataset in your scientific research, please cite the following references (Wei et al., EST, 2022; Wei et al., ACP, 2023; Yang et al., ACP, 2026): Wei, J., Liu, S., Li, Z., Liu, C., Qin, K., Liu, X., Pinker, R., Dickerson, R., Lin, J., Boersma, K., Sun, L., Li, R., Xue, W., Cui, Y., Zhang, C., and Wang, J. Ground-level NO2 surveillance from space across China for high resolution using interpretable spatiotemporally weighted artificial intelligence. Environmental Science & Technology, 2022, 56(14), 9988–9998. https://doi.org/10.1021/acs.est.2c03834 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 ChinaHighNO2 dataset is also available for periods prior to 2019, but at a spatial resolution of 10 km: all (including daily) data for the years 2008–2018 is accessible at: https://doi.org/10.5281/zenodo.4641542 More CHAP datasets for different air pollutants are available at: https://weijing-rs.github.io/product.html

Note that the data are recorded in local time (i.e., Beijing Time, GMT+8) and measured under room conditions (i.e., 298 K and 1013 hPa). This dataset is continuously updated. If you require additional data for related scientific research, please contact us (jingwei@pku.edu.cn or weijing.rs@gmail.com).