NASA’s sensor produces the first global maps of surface minerals in arid regions

EMIT presents first-of-its-kind maps of minerals in dust source regions on Earth, enabling scientists to model the role of fine particulate matter in climate change and more.

NASA’s EMIT mission has created the world’s first comprehensive maps of mineral dust source regions, providing precise locations of 10 major minerals based on how they reflect and absorb light. When wind lifts these materials into the air, they either cool or warm the atmosphere and Earth’s surface, depending on their composition. Understanding their abundance around the world will help researchers predict future climate impacts.

Launched to the International Space Station in 2022, EMIT, short for Earth Surface Mineral Dust Source Investigation, is an imaging spectrometer developed by NASA’s Jet Propulsion Laboratory in Southern California. The mission fulfills climate scientists’ critical need for more detailed information about surface mineral composition.

By scanning the Earth’s surface from about 250 miles (410 kilometers) above, EMIT surveys large areas that would be impossible for a geologist on the ground or instruments carried by aircraft to survey, yet it does so while effectively achieving the same level of detail.

So far, the mission has captured more than 55,000 “views” — 50 by 50 miles (80 by 80 kilometers) images of the surface — in its study area, which includes barren regions within a 6,900-mile radius. A wide belt (11,000 km wide) around the middle of the Earth. Together, the views include billions of measurements, more than enough to create detailed maps of surface composition.

The mission also demonstrated a range of additional capabilities during its 17 months in orbit, including detecting methane and carbon dioxide plumes emanating from landfills, oil facilities and other infrastructure.

“Wherever we need chemistry to understand something on the surface, we can do that using imaging spectroscopy,” said Roger Clark, a member of the EMIT science team and chief scientist at the Planetary Science Institute in Tucson, Arizona. “Now, with EMIT, we’ll see the big picture, and that will definitely open some eyes.”

Dust and climate

Scientists have long known that airborne mineral dust affects climate. They know that dark materials rich in iron oxide absorb the sun’s energy and warm the surrounding air, while brighter materials without iron reflect light and heat, cooling the air. However, whether these effects have a net warming or cooling effect remains uncertain.

Researchers have an idea of ​​how dust moves through the atmosphere, but the missing piece is the texture — the color — of the surface in places where dust typically originates, which has so far been extracted from fewer than 5,000 sample sites around the world. . Based on billions of samples, the EMIT maps provide much more detail.

“We will take the new maps and put them into our climate models,” said Natalie Mahowald, deputy principal investigator at EMIT and an Earth system scientist at Cornell University in Ithaca, New York. “From that, we will know what fraction of aerosols absorb heat versus what reflects it to a much greater extent than we have known in the past.”

Dust and ecosystems

In addition to harnessing EMIT’s mineral data to improve Earth’s climate modeling, scientists can use the information to study the impact of dust on the ecosystems in which it lands. There is strong evidence that particles settling in the ocean can stimulate phytoplankton blooms, which could have implications for aquatic ecosystems and the planet’s carbon cycle. Scientists have also shown that dust originating in the Andes in South America, as well as in parts of northern and sub-Saharan Africa, provides nutrients for the growth of rainforests in the Amazon Basin.

EMIT data could enable researchers to pinpoint the sources of mineral dust and take a more detailed look at its composition, helping to estimate the transport of key elements such as phosphorus, calcium and potassium, which are thought to influence this enrichment over long distances.

“EMIT can help us build more complex and accurate models of dust transport to track the movement of those nutrients over long distances,” said Eric Slesarev, a soil researcher at Yale University in New Haven, Connecticut. “This will help us better understand soil chemistry in places far removed from dust-generating areas.”

A new generation of science

Aside from tracking the 10 key minerals that are part of its core mission, EMIT data is used to identify a range of other minerals, plant species, snow and ice, and even human-produced materials on or near the Earth’s surface. As more measurements become available, researchers will be able to find statistical relationships between surface properties and other features of interest.

For example, they might detect signals in the EMIT data consistent with the presence of rare earth elements and lithium-bearing minerals, said Robert Green, a senior research scientist at JPL and a principal investigator at EMIT. This new information can be used to search for these materials in previously unknown places.

“Until this moment, we simply didn’t know the distribution of surface minerals over vast swaths of the planet,” said Phil Broderick, a data scientist at JPL who led the creation of the mineral maps. With the EMIT data, “a new generation of science is likely to emerge that we don’t know anything about yet, and that’s a really cool thing.”

More about the 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.

To learn more about the mission, visit:

https://earth.jpl.nasa.gov/emit/

News media communications

Andrew Wang/Jin J. Lee
Jet Propulsion Laboratory, Pasadena, California.
626-379-6874 / 818-354-0307
andrew.wang@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov

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