Since its launch 16 months ago, the EMIT Imaging Spectrometer aboard the International Space Station has demonstrated the ability to detect more than just surface minerals.
More than a year after first detecting plumes of methane from its position aboard the International Space Station, data from NASA’s EMIT instrument is now being used to identify point-source emissions of greenhouse gases with greater skill. which has surprised even its designers.
EMIT, short for Earth Surface Mineral Dust Source Investigation, was launched in July 2022 to map 10 key surface minerals in the world’s arid regions. Those observations related to minerals, which are already available to researchers and the public, will help improve understanding of how dust rising into the atmosphere affects the climate.
Methane detection was not part of EMIT’s primary mission, but the instrument’s designers hoped the imaging spectrometer would have that capability. Now, with more than 750 emissions sources identified since August 2022 (some small, others in remote locations, and others persistent over time), the instrument has more than delivered in that regard, according to a new study published in Scientific advances.
“At first we were a little cautious about what we could do with the instrument,” said Andrew Thorpe, a research technologist on the EMIT science team at NASA’s Jet Propulsion Laboratory in Southern California and lead author of the paper. “It has exceeded our expectations.”
By knowing where methane emissions come from, operators of landfills, agricultural sites, oil and gas facilities, and other methane producers have the opportunity to address them. Tracking human-caused methane emissions is key to limiting climate change because it offers a rapid and comparatively low-cost approach to reducing greenhouse gases. Methane remains in the atmosphere for about a decade, but during this time it is up to 80 times more powerful at trapping heat than carbon dioxide, which remains for centuries.
EMIT has proven effective at detecting both large (tens of thousands of pounds of methane per hour) and surprisingly small (up to hundreds of pounds of methane per hour) emission sources. This is important because it allows a greater number of “super-emitters” to be identified, sources that produce disproportionate proportions of total emissions.
The new study documents how EMIT, based on its first 30 days of greenhouse gas detection, can observe between 60% and 85% of the methane plumes typically seen in aerial campaigns.
At several thousand feet above the ground, methane-detection instruments on airplanes are more sensitive, but to justify sending a plane, researchers need prior indication that they will detect methane. Many areas are not examined because they are considered too remote, too risky or too expensive. Furthermore, the campaigns carried out cover relatively limited areas for short periods.
On the other hand, from an altitude of about 400 kilometers (250 miles) on the space station, EMIT collects data over a large swath of the planet, specifically the arid regions lying between 51.6 degrees north and south latitude. The imaging spectrometer captures 80 kilometers by 80 kilometers (50 miles by 50 miles) images of the surface (researchers call them “scenes”), including many regions that have been out of reach of airborne instruments.
“The number and scale of methane plumes measured by EMIT around our planet is striking,” said Robert O. Green, senior research scientist at JPL and EMIT principal investigator.
To support source identification, the EMIT science team creates methane plume maps and publishes them on a websitewith underlying data available from the USGS-NASA Earth Processes Distributed Active Archive Center (LP-DAAC). Data from the mission is available for use by the public, scientists and organizations.
Since EMIT began collecting observations in August 2022, it has documented more than 50,000 scenes. The instrument detected a group of emissions sources in a poorly studied region of the world. southern Uzbekistan on September 1, 2022, detecting 12 plumes of methane totaling approximately 49,734 pounds (22,559 kilograms) per hour.
In addition, the instrument has detected much smaller columns than expected. Captured in a remote corner of southeastern Libya On September 3, 2022, one of the smallest sources so far was emitting 979 pounds (444 kilograms) per hour, based on local wind speed estimates.
More about the mission
EMIT was selected from the Earth Venture Instrument-4 tender under the Earth Sciences Division of NASA’s Science Mission Directorate and was developed at NASA’s Jet Propulsion Laboratory, managed for the agency by Caltech in Pasadena. , California. Data from the instrument are available at NASA’s Earth Process Distributed Active Archive Center for use by other researchers and the public.
For more information about the mission, visit:
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