Abstract:
In order to explore the O
3 pollution pattern of typical urban agglomerations in China (Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta) in recent years, the OMI-MLS (Ozone Monitoring Instrument-Microwave Limb Sounder) tropospheric O
3 column data from 2005 to 2020 and the surface O
3 concentration monitoring data from 2015 to 2020 were collected to analyze the temporal and spatial distribution characteristics and the evolution trend of O
3 in the three urban agglomerations. The results were showed as follows: (1) The monthly peak and annual average values of the total tropospheric O
3 column were Beijing-Tianjin-Hebei > Yangtze River Delta > Pearl River Delta. The total tropospheric O
3 column amounts in the urban agglomerations of the Beijing-Tianjin-Hebei and the Yangtze River Delta were the highest in summer (regional average 50.0 and 44.4 DU (dobson unit) respectively), while the total tropospheric O
3 column in the urban agglomeration of Pearl River Delta was the highest in spring (regional average 42.2 DU). (2) The total amounts of tropospheric O
3 column of the three urban agglomerations had different characteristics in spatial distribution, showing a trend of high in the southeast and low in the northwest of the Beijing-Tianjin-Hebei, and showing a upward trend with increasing latitude in the Yangtze River Delta. However, the difference in the total amount of tropospheric O
3 column between the north and the south of the Pearl River Delta was small. One of the common features in the three urban agglomerations was that the higher the altitude, the lower the total amount of tropospheric O
3 column. (3) The total amount of O
3 column in the Beijing-Tianjin-Hebei, the Yangtze River Delta and the Pearl River Delta urban agglomerations increased significantly year by year, with average annual increase of 0.25, 0.28 and 0.27 DU, respectively. The Beijing-Tianjin-Hebei urban agglomeration increased the most in autumn and winter when the total amount of O
3 column was low (0.29 DU), while the Yangtze River Delta and the Pearl River Delta increased the most in summer and spring when the total amount of O
3 column was the highest (both were 0.39 DU), respectively. (4) The correlation between the total amount of O
3 column detected by the satellite and the maximum daily 8 h moving average of O
3 (O
3-8 h) concentration monitored by ground atmospheric environmental observations was obvious in the Beijing-Tianjin-Hebei and the Yangtze River Delta urban agglomerations, while the correlation was poor in the Pearl River Delta urban agglomeration. (5) The O
3-8 h concentration was also the Beijing-Tianjin-Hebei > the Yangtze River Delta > the Pearl River Delta. The O
3-8 h concentration in the urban agglomeration of Beijing-Tianjin-Hebei was the highest in 2018 (110.9 μg/m
3). The O
3-8 h concentration spatially changed from high in the north and low in the south before 2016 to the opposite characteristic. In most cities, O
3 pollution was serious and the compliance rate was low. The O
3-8 h concentration in the urban agglomeration of Yangtze River Delta was the highest in 2017 (106.7 μg/m
3), the high concentration center of O
3-8 h gradually shifted from the northeast to the west from 2016. The compliance rate of coastal cities gradually increased. The degree of O
3 pollution in the urban agglomeration of the Pearl River Delta was the lowest, and many cities met the standard. However, the O
3-8 h concentration increased year by year and reached the highest in 2019 (100.4 μg/m
3). The increase in O
3-8 h concentration in central cities was much higher than that in peripheral cities. Overall, the temporal and spatial distribution characteristics of total amount of O
3 column and the O
3-8 h concentration were different significantly in the three major urban agglomerations in China, and the factors that cause the differences were also different.
下载: