OMI measurements show a decrease in SO₂ amounts over the Eastern United States

The Ozone Monitoring Instrument (OMI) data confirm a substantial reduction in sulfur dioxide (SO₂ ) values around the largest US coal power plants as a result of the implementation of SO₂ pollution control measures.

Mean SO₂ values for 2005-2007

Mean SO₂ values for 2008-2010

The figure shows average SO₂ values measured by OMI on the NASA Aura spacecraft for the periods 2005-2007 and 2008-2010 over the Eastern US where the majority of large SO₂ sources are located. Scientists use this information to identify anthropogenic sources of SO₂ and to estimate their emission rates. The greatest values are in violet; the lowest in green. Yellow to violet colors correspond to statistically significant enhancements in SO₂ pollution in the vicinity of the largest SO₂ emitting coal-burning power plants indicated by the black dots.

Previous use of space-based SO₂ retrievals has been limited to monitoring plumes from volcanic eruptions and detecting anthropogenic emissions from large source regions as in China. A new spatial filtration technique allows the detection of individual pollution sources in Canada and the US.

Credit : Fioletov, V., et al., (2011), Geophysical Research Letters, in press

10.21.2011