Vitali Fioletov of Environment Canada in Toronto reported results based on data from 2005 through 2010 returned by the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite. Aura (Latin for air) satellite, the third element of the Earth Observing System (EOS), was launched in 2004 as part of a multi-national research effort to gather data on Earth's water and air quality.
Aura (EOS CH-1) is a multi-national NASA scientific research satellite in orbit around the Earth, studying the Earth's ozone layer, air quality and climate. It is the third major component of the Earth Observing System (EOS) following on Terra (launched 1999) and Aqua (launched 2002). Aura follows on from the Upper Atmosphere Research Satellite (UARS).Wiki
It isn't often we have visual confirmation of the difference between a Republican administration and a Democratic one, but this study does just that. Jump below the cloud to see for yourself.
Dr. Fioletov and his colleagues developed a powerful technique to determine SO₂ concen- trations and average them over specific time periods.
While scientists have used the Ozone Monitoring Instrument to observe sulfur dioxide levels within large plumes of volcanic ash and over heavily polluted parts of China in the past, this is the first time they have observed such subtle details over the United States, a region of the world that in comparison to fast-growing parts of Asia now has relatively modest sulfur dioxide emissions. Just a few decades ago, sulfur dioxide pollution was quite severe in the United States. Levels of the pollutant have dropped by about 75 percent since the 1980s due largely to the passage of the Clean Air Act.NASA
The US has made some considerable progress reducing the level of the ozone producing pollutant sulfur dioxide since the passage of the Clean Air Act (most recent revision in 1990) as can be seen below.
The new technique allowed Fioletov's team to pinpoint sources of sulfur dioxide from 40 of the largest sources in the United States. Below we see maps of the concentrations over the mid-southeast over the periods 2005-2007 and 2008-2010.
Essentially the study calibrated its results against data from US coal fired power plants. US coal plants have SO₂ monitoring instruments installed in their smoke stacks which have, since 2005, recorded a 46% decrease in sulfur dioxide emissions. As the new technique reports a highly correlated 40% decrease in emissions scientists and regulating agencies now have a satellite based tool to monitor pollution where stack based instrumentation does not exist.
"What we’re seeing in these satellite observations represents a major environmental accomplishment," said Bryan Bloomer, an Environmental Protection Agency scientist familiar with the new satellite observations. "This is a huge success story for the EPA and the Clean Air Interstate Rule," he said."NASA
It occurs to me that Dr. Bloomer is being carefully apolitical.