| Ozone plays an important role in global and regional atmospheric environmental changes,and has a significant environmental effect as the primary pollutant in the atmosphere.In this paper,based on the atmospheric environmental air quality monitoring network data and the long-term historical observation data of some pilot cities,we studies the pollution status of near-surface ozone pollution in China,Spatio-temporal variation and precursors.The ozone pollution characteristics,influencing factors,and regional management of China were organically combined,and the concentration distribution of ozone and its major influencing factors were correlated and analyzed to obtain the main control factors that led to ozone pollution in typical regions.Through PMF model,stepwise regression and other statistical analysis methods,the main components and sources of ozone precursor VOCs in typical cities were obtained,and the effects of main meteorological factors and particulate pollution on the change of ozone concentration were obtained.The rotation correlation orthogonal function method(REOF)was introduced innovatively to partition the characteristics of atmospheric pollution in China.Time-coefficients were used to characterize the characteristics of ozone concentration over time,and used as a basis for the division of ozone management zones.The main results are as follows:(1)In 2015,China’s annual average concentration range of ozone was36.9-118.2μg/m~3,exceeding the standard rate of 16%;2016,the annual average concentration range of ozone was 47.3-119.8μg/m~3,and the over-standard rate was17.5%.The situation of ozone pollution in the Beijing-Tianjin-Hebei region and the Yangtze River Delta region has been increasing year by year,the overall trend of the Pearl River Delta region has eased,and the country’s ozone pollution has been on the rise.(2)Ozone pollution in China has obvious seasonal variations and spatial variations.The ozone pollution in the Beijing-Tianjin-Hebei region is characterized by a single peak,with the peak mainly in May-July;the Yangtze River Delta region is characterized by two peaks,with the peak concentration mainly in May-June and August-September;The pollution in the Pearl River Delta region was particularly severe in autumn,with peaks appearing in October.The cities with the most serious ozone pollution are located in North China,followed by Central and East China.(3)Through in-depth analysis of measured data of ozone precursor VOCs in eight typical cities in North China and Central China,it is known that olefin contributes the most to the OFP(59.24%-79.81%),and the 8 sites of ozone production are mainly controlled by VOCs.The main sources of VOCs in cities are gasoline evaporation,LPG/NG leakage,vehicle emission,coal burning,biogenic emissions,and solvent usage and paint evaporation.(4)Using the NAQPMS numerical model method,multi-angle adjustment of VOCs emission sources has effectively improved the forecasting effect.The model was used to simulate and predict the ozone pollution of Hangzhou and Shanghai during the same period.The results show that the model is a good predictor of ozone concentration and change trend over the next week,and in particular,it can predict ozone peaks very well.(5)The REOF analysis was conducted on the annual average concentration of ozone of 338 cities in 2015.According to the obtained model,China was divided into12 ozone pollution characteristics regions.The time variation coefficient of each model was analyzed.The results show that the characteristics of ozone concentration in the same model over time are consistent. |
