Spatially continuous mapping of hourly ground ozone levels assisted by Himawari-8 short wave radiation products

ABSTRACT

Ground-level ozone concentration has demonstrated a noteworthy increasing trend in easternChina over the past 20 years, exerting inescapable influence on atmospheric chemistry, climate change, and air pollution. To support epidemiological research and prevent further environmental pollution, it is imperative to monitor the spatio-temporal distribution of ground-level ozone pollution. Geostationary satellites prove a promising approach to make up for the limitation of ground-based measurement and polar-orbiting observation by acquiring regional atmospheric measurements of high spatio-temporal resolution, yet inevitably exists spatial discontinuity caused by the cloud cover. This study established an effective model to produce spatially continuous estimation of hourly 5 km ground-level ozone (O₃) concentrations covered most of China by firstly integrating hourly Himawari-8 SWR product from 1 March 2018 to 28 February 2019. The R² values of established model of all available samples for direct fitting, 20-fold cluster-based CV, 10-fold site-based CV, and 10-fold sample-based CV reaches 0.95, 0.69, 0.87 and 0.89, respectively, implying superior universality and spatial scalability. The R² values of seasonal site-based CV range from 0.78 (Winter) to 0.86 (Autumn), and that of hourly site-based CV ranges from 0.73 (0900 BST) to 0.86 (1300 BST). In addition, this study displayed the spatial distribution of the estimated ground-level ozone from the temporal scales of quarter, week, and day. Summer (87.1 ± 28.2 μg/m³) proves to be the most polluted season, and the least polluted season is winter (59.4 ± 16.1 μg/m³). 1400 BST appears to be the most polluted hour (87.4 ± 26.6 μg/m³) and 0900 BST is the least polluted hour (59.1 ± 16.8 μg/m³). Remarkable “weekend effect of ozone” has been detected in northeast Hebei and Sichuan Basin and Yangtze River valley.

Acknowledgments

We are grateful to CNEMC, the Japan Aerospace Exploration Agency, ERA5, the data center of NASA, and USGS for providing the datasets used in this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The raw data used in this study are publicly available from the sources provided in following links. The processed data generated from this study are available upon request to the corresponding author.

- Surface O₃ in situ data: http://www.cnemc.cn/

- Short Wave Radiation L3 data and Aerosol Property L4 data: https://www.eorc.jaxa.jp/ptree/

- MOP03J_8 L3 data: https://asdc.larc.nasa.gov/project/MOPITT/

- ML2O3_005 L2 data, OMTO3E L3 data, OMI_MINDS_NO2d L3 data, OMHCHOG L2 data, Land Cover Type (MCD12Q1) L3 data and MOD13C1/MYD13C1 L3 data: https://www.earthdata.nasa.gov/

- ERA5 reanalysis data:https://cds.climate.copernicus.eu/cdsapp#!/

- SRTM 90m DEM Digital Elevation: https://srtm.csi.cgiar.org/

Additional information

Funding

The work was supported by the Basic Science-Center Project of National Natural Science Foundation of China [72088101]; the Key Program of the National Natural Science Foundation of China [41930108]; Department of Natural Resources of Hunan Province [(2022)No.5].