A team of scientists from US and Canada used satellite data to identify sources of toxic emissions on Earth. The NASA satellite involved in the project is Aura, which has been orbiting the Earth since 2004 in search of modifications in the atmosphere.
The scientists used the data from Aura to locate no more than 39 sources of sulfur dioxide emissions. The release of toxic substances was not reported by any of the industrial companies in question.
Air Pollution with Sulfur Dioxide
The levels of sulfur dioxide are monitored by base measurements. Scientists make approximations based on other factors that generate emissions, such as the rate of fuel usage.
However, these calculations are not exact, and air measurements made on the ground are not reliable because of the air movements which make it impossible to determine the source of the toxins.
Data produced by the satellite monitoring is much more precise. From space, the sources can be detected by simple analysis of its density in the air and the constancy of pollution in certain zones. Scientists say that they appear like hotspots on atmospheric maps, which lead them directly to the source.
As one of the six pollutants regulated by the US authorities, sulfur dioxide is a significant hazard for health and a contributor to acid rains.
Aura’s Findings
The 39 locations where sulfur dioxide is released are coal power plants, oil and gas operations, and smelters. The ground measurements done on these sites were up to three times lower than data showed from space, as the air dissipates the toxins and raises them into the upper atmosphere.
The percentage of these new sources is up to 12% of the entire man-made pollution. Correcting the situation may have a great impact on improving the air quality.
The NASA satellite helped to identify 75 other natural sources of sulfur dioxide, such as passive volcanoes in remote areas of the globe.
Scientists used advanced computer techniques in order to process the data, due to major technological breakthroughs that came after Aura was sent into the orbit more than ten years ago.
In their analysis, researchers used more precise estimates of air movements and designed a new computer program that will trace pollutants back to their source.
NASA Environmental Project
Aura is a spacecraft designed to investigate environmental issues and the quality of Earth resources. The first task was to monitor the levels of ozone in the stratosphere, which is 50% thinner over Antarctica and presumably produced enough heating to melt the ice.
Another project is related to air pollution, a major mortality factor for the population. The satellite continuously verifies the quality of air and its composites – methane, carbon dioxides, vapors, and aerosols.
The satellite is equipped with a Dutch-Finnish Instrument for ozone monitoring that helps gather real-time information from places all around the globe.
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