SPATIO-TEMPORAL CHARACTERISTICS OF NO2 IN PRD URBAN GROUP AND THE ANTHROPOGENIC INFLUENCES ANALYSIS BASED ON OMI REMOTE SENSING DATA

Spatio-temporal distribution characteristics and variation trends of tropospheric NO2 in Pearl River Delta (PRD) urban group and its adjacent areas were analyze from 2005 to 2013 based on remote sensing data from ozone monitoring instrument (OMI) satellite, and further explored the impact of human activities on NO2. Compared with the ground observation data, the OMI NO2 remote sensing data displayed high reliability. Due to active industrial production, high car ownership, great energy and power consumption, the average tropospheric NO2 concentration (7.4×1015 molec/cm2) of PRD region is about 3 times of the adjacent areas. At the same time, the regional high pollution NO2 in PRD region as a whole, the urban group effect is remarkable. Sinusoidal model can well fit the periodic variation of the NO2 in PRD and adjacent areas. NO2 concentration was highest in winter while lowest in summer. The concentration of NO2 in PRD region is decreasing in recent 9 years, which has a significantly negative correlation with the second industry output and car ownership. This suggests that the nitrogen oxide emissions governance in PRD region had achieved initial results. The concentration of NO2 increased significantly in the eastern and northern Guangdong Province, there are good positive correlations with the second industrial outputs and car ownerships, it is thus clear that industrial emissions and automobile exhausts are important sources of NO2 in these regions. The concentration of NO2 in western Guangdong area is stable.