1. Daily spatiotemporal prediction of surface ozone at the national level in China: An improvement of CAMS ozone product
- Author
-
Boyuan Tang, Hamed Karimian, Shuwei Fang, Qi Li, Yuqin Mo, Sitao Zhang, and Xiaoyang Kong
- Subjects
Atmospheric Science ,Ozone ,010504 meteorology & atmospheric sciences ,Meteorology ,Ozone concentration ,Air pollution ,Empirical orthogonal functions ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,Pollution ,Atmosphere ,Ambient ozone ,chemistry.chemical_compound ,Surface ozone ,chemistry ,medicine ,Environmental science ,National level ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
Accurate nationwide spatiotemporal distribution of ambient ozone product is critical for environment & health departments and for researches to investigate the influence of ozone for epidemiological studies. Our hybrid method, the novel CAMS (The Copernicus Atmosphere Monitoring Service) ozone improvement (CAO3_I) method, is the first attempt to predict ambient ozone by improving CAMS ozone (CAO3) products. For this novel framework, the SVM (Support Vector Machine) has been adopted for classification through the most significant regional ozone patterns which were extracted through the REOF (Rotated Empirical Orthogonal Function) technique. For each classified region, meteorological data, geographical data, CAMS ozone and ground-sites ozone are fed into random forest for regional regulation training and prediction. The CAO3_I method has shown its great feasibility in daily ozone surface distribution prediction. Based on daily averaged ozone concentrations for each station (STO3), the performance of CAO3 products (R2 = 0.35, RMSE = 25.77 μg/m3, MAPE = 42.06) have significantly improved to CAO3_I (R2 = 0.81, RMSE = 14.10 μg/m3, MAPE = 22.37), which shows above 97.4% R2 and RMSE have been improved. Our model is also capable to predict high level ozone concentrations in summer where the R2 has improved from 0.37 (for CAO3) to 0.81. In comparison with ground monitoring stations, the CAMS ozone improvement results can excellently reflect the distribution of daily ground-level ozone concentration and outperform previous statistical models in predicting ambient O3 concentrations. Therefore, the prediction results and our proposed model can be used for future epidemiological studies and air pollution controlling programs.
- Published
- 2021