Chunmei Chen , Xiaomei Chen , Qiong Liu , Weiyu Zhang , Yonghang Chen , Yuhuan Ou , Xin Liu , Huiyun Yang
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引用次数: 0
Abstract
Carbon dioxide (CO2) is one of the most significant greenhouse gases in the atmosphere and plays a crucial role in global warming. Currently, the temporal resolution for XCO2 from the satellite is low, and the ground-based XCO2 observation station is limited. There is an urgent need for a XCO2 dataset with high temporal and spatial resolution. Consequently, based on the random forest algorithm, we have developed an optimized model for predicting XCO2 with a spatial resolution of 0.25° × 0.25° and a temporal resolution of 1 h for the Yangtze River Delta in 2020. The multi-source data, such as the ground-observation XCO2 from the TCCON, as well as meteorological parameters, aerosols, surface vegetation index, and emission source factors from the ERA5, MERRA-2, MODIS, and MEIC datasets, were used in this study. The results indicate that the random forest model is well-suited for predicting XCO2. Specifically, the model performs more optimally when utilizing 20 variables, including solar zenith angle, normalized vegetation index, and carbon emission data as input parameters with the prediction RMSE and R2 of 1.031 × 10−6 and 0.940. The MAE for predicted XCO2 at Xianghe and Hefei stations are 0.628 × 10−6 and 0.550 × 10−6, respectively, marking a substantial increase in accuracy compared to GOSAT data. In 2020, daily variations of XCO2 follow a pattern of higher concentrations at night and lower concentrations during the day, negatively correlating with changes in the atmospheric boundary layer height. The inter-monthly and seasonal variations reveal smaller concentrations in summer and higher concentrations in winter. The minimum concentration occurs in July at 409.64 × 10−6, while the maximum concentration occurs in November at 413.11 × 10−6. Spatially, XCO2 is higher in the northern areas and lower in the southern regions, showing a negative correlation with the NDVI and a positive correlation with anthropogenic carbon emissions. The XCO2 dataset calculated in this study with continuous spatial and temporal resolutions could address the limitations of satellite products with low temporal resolution and a limited number of ground observation stations.
期刊介绍:
Atmospheric Pollution Research (APR) is an international journal designed for the publication of articles on air pollution. Papers should present novel experimental results, theory and modeling of air pollution on local, regional, or global scales. Areas covered are research on inorganic, organic, and persistent organic air pollutants, air quality monitoring, air quality management, atmospheric dispersion and transport, air-surface (soil, water, and vegetation) exchange of pollutants, dry and wet deposition, indoor air quality, exposure assessment, health effects, satellite measurements, natural emissions, atmospheric chemistry, greenhouse gases, and effects on climate change.