Analyzing the spatial and temporal variations in tropospheric NO2 column concentrations over China using multisource satellite remote sensing

Abstract

We comprehensively considered the spatial resolution and seasonal differences in NO2 column concentration data observed by different satellites to reconstruct an NO2 column concentration dataset in China from 1997 to 2018. On this basis, the spatial and temporal variations in NO2 column concentrations were analyzed over China from 1997 to 2018. The results show that the reconstructed NO2 column concentration dataset with high spatial structure characteristics in China from 1997 to 2018 effectively compensates for the lack of long-term high-resolution monitoring of NO2 pollution in China by a single satellite. (The accuracy of the reconstructed dataset was verified by season: correlation coefficient between GOME and SCIAMACHY, R > 0.87, P 0.91, P < 0.01.) The analysis of the spatial and temporal variations showed that the NO2 column concentrations in China from 1997 to 2018 generally showed high values in the east and low values in the west. The high concentrations of NO2 are mainly concentrated in the northern and eastern coastal areas and the Pearl River Delta. From 1997 to 2010, the NO2 column concentrations continued to increase with a growth rate of ( 0.180 ± 0.011 ) × 1015 molec / ( cm2 a ) over China. From 2011 to 2018, the NO2 column concentrations showed a downward trend, with a decreasing rate of ( 0.144 ± 0.037 ) × 1015 molec / ( cm2 a ) over China. After 2011, NO2 pollution in high pollution regions such as Beijing, Tianjin, Hebei, Shandong, the Yangtze River Delta, and the Pearl River Delta was alleviated. Energy saving and emission reduction measures can reduce nitrogen dioxide pollution while ensuring sustained gross domestic product (GDP) growth.