Unveiling Greenhouse Gas Emission Sources

The Earth Surface Mineral Dust Source Investigation (EMIT) on the International Space Station proves adept at detecting methane plumes, unveiling unexpected emissions data.

NASA’s EMIT (Earth Surface Mineral Dust Source Investigation) mission, launched just over a year ago with the primary goal of mapping minerals in arid regions, has achieved remarkable success in an unexpected realm. The EMIT imaging spectrometer aboard the International Space Station has emerged as a proficient detector of greenhouse gas emissions, specifically methane.

Although methane detection was not the primary mission, EMIT’s designers anticipated its capability. Surprisingly, the instrument has identified over 750 emissions sources since August 2022, ranging from small and remote to persistent over time. This revelation surpasses expectations, as detailed in a recent study published in Science Advances.

Andrew Thorpe, a research technologist on the EMIT science team, expressed, “We were a little cautious at first about what we could do with the instrument. It has exceeded our expectations.”

Understanding the origin of methane emissions is crucial for addressing them effectively. With the ability to identify emissions from landfills, agriculture sites, oil and gas facilities, and other sources, operators have an opportunity to take corrective actions. This is vital in the fight against climate change, considering that methane is significantly more potent at trapping heat than carbon dioxide.

One notable aspect of EMIT’s performance is its effectiveness in detecting emissions from both large and surprisingly small sources. This capability allows for the identification of a greater number of “super-emitters,” which contribute disproportionately to total emissions.

In a groundbreaking development, EMIT, in its first 30 days of greenhouse gas detection, demonstrated an ability to observe 60% to 85% of methane plumes typically detected in airborne campaigns. While instruments on aircraft are more sensitive from a lower altitude, they are limited by the need for prior indications of methane presence.

EMIT, orbiting about 250 miles above the Earth’s surface on the space station, captures data over a large area, specifically the arid regions between 51.6 degrees north and south latitude. The imaging spectrometer provides 50-mile-by-50-mile images, referred to as “scenes,” covering regions that were previously beyond the reach of airborne instruments.

Robert O. Green, EMIT’s principal investigator, remarked, “The number and scale of methane plumes measured by EMIT around our planet is stunning.”

To aid source identification, the EMIT science team generates maps of methane plumes, making them available on a website. The underlying data is accessible through the joint NASA-United States Geological Survey Land Processes Distributed Active Archive Center (LP DAAC).

Since August 2022, EMIT has documented over 50,000 scenes, showcasing its ability to identify emission sources, from large clusters in Uzbekistan to unexpectedly small plumes in remote areas of Libya.

NASA’s EMIT mission stands as a testament to the unexpected discoveries that space-based technology can unveil, contributing valuable data to address environmental challenges on Earth.

Source: Nasa

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