NASA’s unlikely hero in the climate crisis

Since its launch 16 months ago, it has been the EMIT imaging spectrometer on board the spacecraft International Space Station Demonstrated ability to detect more than just surface minerals.

More than a year after plumes of methane were first detected from its perch aboard the International Space Station (ISS), data from NASA’s EMIT instrument are now being used to determine greenhouse gas emissions from a stationary source with an efficiency that surprised even its designers.

EMIT’s mission and capabilities

EMIT, an acronym for Earth Surface Mineral Dust Source Investigation, was launched in July 2022 to map ten key minerals on the surface of the world’s arid regions. Those notes related to minerals, which are already available to Researchers And the public, they will help improve understanding of how dust rising into the atmosphere affects the climate.

Detecting methane was not part of EMIT’s primary mission, but the instrument’s designers expected the imaging spectrometer to have the capability. Now, with more than 750 emissions sources identified since August 2022 — some small, some in remote locations, and some persisting over time — the tool has done more than it gives in this regard, according to a new study published in the journal. Advancement of science.

EMIT identified a group of 12 methane plumes in a 150-square-mile (400-square-kilometer) area in southern Uzbekistan on September 1, 2022. The instrument captured the group in a single snapshot, which researchers called a scene. Image source: NASA/JPL-Caltech

Methane emissions and climate change

“We were a bit cautious at first about what we could do with the instrument,” said Andrew Thorpe, a research technology expert on the EMIT science team at the University of California. NASAJet Propulsion Laboratory in Southern California and lead author of the paper. “It exceeded our expectations.”

By knowing the source of methane emissions, operators of landfills, agricultural sites, oil and gas facilities, and other methane producers have the opportunity to address these emissions. Tracking human-caused methane emissions is key to reducing climate change because it provides a quick and relatively low-cost approach to reducing greenhouse gases. Methane remains in the atmosphere for about a decade, but during this period, it is up to 80 times stronger at trapping heat than carbon dioxide, which remains for centuries.

When strong winds on one continent stir up mineral rock dust (such as calcite or chlorite), airborne particles can travel thousands of miles to impact entirely different continents. Dust suspended in the air can heat or cool the atmosphere and Earth’s surface. This heating or cooling effect is the focus of NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) mission. Image source: NASA/JPL-Caltech

Amazing results

EMIT has proven effective in detecting sources of emissions that are both large (tens of thousands of pounds of methane per hour) and surprisingly small (up to hundreds of pounds of methane per hour). This is important because it allows for the identification of a greater number of “super emitters” – sources that produce disproportionate shares of total emissions.

The new study documents how, based on the first 30 days of greenhouse gas detection, EMIT can observe 60% to 85% of the methane plumes typically seen in airborne campaigns.

In a remote corner of southeastern Libya, EMIT on September 3, 2022 discovered a methane plume that was emitting about 979 pounds (444 kilograms) per hour. It is one of the smallest sources yet discovered by the device. Image source: NASA/JPL-Caltech

Compare with airborne detection

At several thousand feet above the ground, methane detectors on aircraft are most sensitive, but to guarantee a plane is dispatched, researchers need an advance indication that they will detect methane. Many areas are not examined because they are considered too remote, too risky or too expensive. In addition, the campaigns that occur cover relatively limited areas for short periods.

On the other hand, from an altitude of about 250 miles (400 kilometers) on the space station, EMIT is collecting data over a large swath of the planet — specifically the arid regions between 51.6 degrees north and south latitude. The imaging spectrometer takes images of the surface with dimensions of 50 by 50 miles (80 kilometers by 80 kilometers) — researchers call them “scenes” — including many areas that were once out of reach of airborne instruments.

Robert O. said: “The number and size of methane plumes measured by EMIT around our planet is staggering,” said Green, a biochemist. Jet Propulsion Laboratory Senior Research Scientist and Principal Investigator at EMIT.

This time-lapse video shows the International Space Station’s Canadarm2 robotic arm maneuvering NASA’s EMIT mission on the outside of the station. Extract from SpaceX The Dragon spacecraft was launched at approximately 5:15 PM PT on July 22 and completed at 10:15 AM PT on July 24. Parts of the installation have been deleted, while other parts have been sped up. Credit: NASA

Revealing scene after scene

To support source identification, the EMIT science team creates maps of methane plumes and releases them on… websitewith underlying data available at the Joint NASA/US Geological Survey Operations Distributed Active Archive Center (LB Duck). Mission statements are available for use by the public, scholars, and organizations.

Since EMIT began collecting observations in August 2022, it has documented more than 50,000 sightings. The tool detected a range of emissions sources in a region that has rarely been studied Southern Uzbekistan On September 1, 2022, 12 plumes of methane gas were detected totaling about 49,734 pounds (22,559 kg) per hour.

In addition, the instrument detected plumes that were much smaller than expected. It was taken in a remote corner of Southeastern Libya On September 3, 2022, one of the smallest sources yet was emitting 979 pounds (444 kilograms) per hour, based on local wind speed estimates.

Reference: “Attributing individual methane and carbon dioxide emission sources using EMIT observations from space” by Andrew K. Thorpe, Robert O. Green, David R. Thompson, Philip G. Brodrick, John W. Chapman, Clayton D. Elder, Itziar Irakolis -Loitkesat, Daniel H. Cosworth, Alana K. Ayasi, Riley M. Dorren, Christian Frankenberg, Louis Guenther, John R. Worden, Philip E. Dennison, Dar A. Roberts, K. Dana Chadwick, Michael L. Eastwood, J.E. Vahlin and Charles E. Miller, November 17, 2023, Advancement of science.
doi: 10.1126/sciadv.adh2391

More about EMIT’s mission

EMIT was selected from the Earth Venture Instrument-4 solicitation within the Earth Sciences Division of NASA’s Science Mission Directorate and was developed at NASA’s Jet Propulsion Laboratory, which is operated by the California Institute of Technology in Pasadena, California. Instrument data are available at NASA’s Earth Operations Distributed Active Archive Center for use by other researchers and the public.