Spatiotemporal variations of tropospheric SO_2 over China by SCIAMACHY observations during 2004-2009

摘要

This paper presents results of measurements of tropospheric sulphur dioxide (SO_2) from satellite over China during 2004-2009. SCIAMACHY/ENVISAT SO_2 data products have been validated by ground based remote sensing instrument MAXDOAS in China, and with predictions of the atmospheric model GEOS-Chem. The spatial and temporal distribution of tropospheric SO_2 over China is discussed in this study. The result shows that the SO_2 load over East China is decreasing since strong control for pollution emission in 2007 for preparation of 2008 Olympic Games in China, while the SO_2 load in West China is increasing all the way during 2004-2009, which might reflect that the anthropogenic activity was added to promote the economy development in west of China. Typical seasonal variation with high pollution levels in winter and low in summer is found in the northwest of China, while the inverse seasonal variation is found for the south of China. The characteristics of tropospheric SO_2 over the major cities in China were explored and found that tropospheric SO_2 was partly under control from 2007 because of the policy from China government for reduction in SO_2 emissions in 2006. And the SO_2 value shows remarkably decrease in most of the major cities after 2007 because strong control for the pollution emission for 2008 Olympic games. Guangzhou city shows high SO_2 pollution levels in summer time, since most of the coal power plants and thermal power industry are located to the south of Guangzhou city and southerly winds dominate during summer time.