David J. Phillip/AP/File
Exhaust rises from smokestacks in front of piles of coal at NRG Energy's W.A. Parish Electric Generating Station in Thompsons, Texas, in March 2011. Images from NASA's Aura Spacecraft have helped researches locate 39 severe and unreported man-made sources of toxic sulphur dioxide emissions coming from such sources as power plants and other industrial facilities.

Satellite imagery helps NASA find unreported sources of air pollution

In a recent collaborative study, NASA, along with Environment and Climate Change Canada and two universities, located major previously unknown sources of air pollution.

In parts of the Middle East, Russia, and Mexico, the air is more polluted by factories and power plants than previously thought. 

NASA, in conjunction with Environment and Climate Change Canada and two independent universities – The University of Maryland, College Park and Dalhousie University in Halifax, Nova Scotia – has located 39 severe and unreported man-made sources of toxic sulfur dioxide emissions.

Sulfur dioxide (SO2), one of the six air pollutants regulated by the US Environmental Protection Agency – along with carbon monoxide, ground-level ozone, lead, nitrogen oxides, and particulate matter – is one of a group of highly reactive gases known as "oxides of sulfur," according to the EPA. The greatest contributor of SO2 emissions into the air comes from large-scale fossil fuel combustion, such as that at power plants and other industrial facilities. Lesser contributors include large-ships, locomotive engines, and nonroad equipment.

While reporting on SO2 emissions has been ground-based, gathered from statistics such as fuel usage, the most recent method developed by the collaboration of scientists utilized satellite imagery to locate massive and previously unreported or underreported contributors of SO2 into the air.

"When you look at a satellite picture of sulfur dioxide, you end up with it appearing as hotspots – bull's-eyes, in effect – which makes the estimates of emissions easier," said Chris McLinden, an atmospheric scientist with Environment and Climate Change Canada, as well as the primary author of the recently published study in Nature Geosciences. "We now have an independent measurement of these emission sources that does not rely on what was known or thought known."

Combined, the 39 unreported or underreported sulfur dioxide sources, which were found mostly in the Middle East and around the Persian Gulf – though also in parts of Russia and Mexico – contribute roughly 12 percent of all human-related SO2 emissions. That discrepancy can have a massive impact on regional air quality, according to Mr. McLinden. 

Sulfur dioxide is a pungent, irritating chemical which is directly related and even considered a precursor to acid rain as well as greater percentages of atmospheric particulates – solid and liquid particles such as dust, smoke, pollen, etc. that are suspended in air. Coal and oil-burning power plants contribute a great deal of SO2 into the air; however until recently, reporting exact numbers of SO2 emissions was problematic due to a lack of monitoring capabilities.

Now, utilizing raw satellite observations from an instrument aboard NASA's Aura Spacecraft, scientists are able to view these "hotspots" over time and make precise estimates of SO2 concentrations. The scientists were also able to track sulfur dioxide wind dispersion by accurately estimating wind strength and direction based on satellite information and were able to trace SO2 back to their sources and calculate how much had been omitted over a period of time.

Along with the 39 man-based SO2 emission sites found by the team of scientists, they also discovered 75 sources of natural sulfur dioxide emissions, many of which are located in remote and unmonitored locations; sites such as nonactive volcanoes which slowly leak previously unmeasured amounts of SO2 into the air. 

By utilizing these new techniques, scientists will be better able to monitor the amount of sulfur dioxide being emitted into the atmosphere – a potentially major environmental breakthrough.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Satellite imagery helps NASA find unreported sources of air pollution
Read this article in
QR Code to Subscription page
Start your subscription today