SHI Yiqiang, ZHAO Dinglong, WANG Cuiping, XIAO Zhongyong, LIN Xiaofeng, LIU Shanhong
Based on OMI data product, the spatio-temporal variabilities characteristics of ozone column concentration and its correlation with influential factors in Fujian province are analysed using spatial information technology and Pearson correlational analysis method for the period of 2011 to 2020. The results show that the lowest monthly average value was 260.10 DU in April and the highest 283.97 DU in October. The monthly change was wavy, the order of seasonal mean values was autumn, summer, winter and spring, with autumn being obviously higher than the other three.. The variation range of annual average values was 265.18-275.09 DU, the lowest in 2013 and the highest in 2014, and the total mean value of ozone in recent 10 years was 270.19 DU. In terms of spatial distribution, monthly averages were generally distributed as a relatively high value area from July to December and as a relatively low value area from January to June. The spatial distribution of the mean values in autumn was in a relatively high area, and latitude changes in autumn and summer were more obvious than those in spring and winter. The spatial distributions of average annual values in 2013 and 2016 were in the relatively low value areas, while 2011, 2012, 2014 and 2018 in relatively high value areas. In the recent ten years, the distribution of the total mean values in the north was higher than that in the south, and the relatively high value areas were mainly in Ningde City, Nanping City and the north of Fuzhou City, while the relatively low value areas were mainly in Zhangzhou City, Xiamen City, and the south of Longyan City and Quanzhou City. The overall trend of distribution of ozone was that the ozone values decreased with the decrease of latitude in the north-south orientation, and it rose from inland areas to coastal areas in the east-west orientation. In terms of correlation of ozone with the influencing factors, temperature and precipitation presented both positive correlation and negative correlation, with positive correlation mainly distributed in coastal cities while negative correlation mainly in inland cities, presenting the characteristics of strong positive correlation gradually changed into strong negative correlation from coastal to inland. For precipitation and ozone, most regions showed negative correlation. The NDVI also showed the coexistence of positive and negative correlations but the area of negative correlation was significantly larger than that of positive correlation, showing a significant negative correlation on the whole.
