Recent large reduction in sulfur dioxide emissions from Chinese power plants observed by the Ozone Monitoring Instrument

摘要

The Ozone Monitoring Instrument (OM I) aboard NASA's Aura satellite observed substantial increases in total column SO_2 and tropospheric column NO_2 from 2005 to 2007, over several areas in northern China where large coal-fired power plants were built during this period. The OMI-observed SO_2/NO_2 ratio is consistent with the SO_2/ NO_x emissions estimated from a bottom-up approach. In 2008 over the same areas, OMI detected little change in NO_2, suggesting steady electricity output from the power plants. However, dramatic reductions of SO_2 emissions were observed by OMI at the same time. These reductions confirm the effectiveness of the flue-gas desulfurization (FGD) devices in reducing SO_2 emissions, which likely became operational between 2007 and 2008. This study further demonstrates that the satellite sensors can monitor and characterize anthropogenic emissions from large point sources.