EMIT delivers first-of-a-kind maps of minerals in Earth’s dust-source areas, enabling scientists to model the fine particles’ role in climate change and more.
NASA’s EMIT mission has created the first comprehensive maps of the world’s mineral dust-source regions, providing precise locations of 10 key minerals based on how they reflect and absorb light. When winds loft these substances into the air, they either cool or warm the atmosphere and Earth’s surface, depending on their composition. Understanding their abundance around the globe 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 fills a crucial need among climate scientists for more detailed information on surface mineral composition.
Surveying Earth’s surface from about 250 miles (410 kilometers) above, EMIT scans broad areas that would be impossible for a geologist on the ground or instruments carried by aircraft to survey, yet it does this while achieving effectively the same level of detail.
EMIT, a NASA mission launched to the International Space Station in 2022, mapped hematite, goethite, and kaolinite in North Africa and the Arabian Peninsula. The three minerals are among 10 key substances the mission studied that are thought to influence climate change. NASA/JPL-Caltech
To date, the mission has captured more than 55,000 “scenes” – 50-by-50-mile
(80-by-80-kilometer) images of the surface – in its study area, which includes
arid regions within a 6,900-mile-wide (11,000-kilometer-wide) belt around
Earth’s mid-section. Taken together, the scenes comprise billions of
measurements – more than enough to create detailed maps of surface composition.
The mission has also demonstrated a
range of additional capabilities in its 17 months in orbit, including detecting plumes of methane and carbon dioxide being emitted by landfills,
oil facilities, and other infrastructure.
“Wherever we need chemistry to
understand something on the surface, we can do that with imaging spectroscopy,”
said Roger Clark, an EMIT science team member and senior scientist at the
Planetary Science Institute in Tucson, Arizona. “Now, with EMIT, we’re going to
see the big picture, and that’s certainly going to open some eyes.”
Dust and
Climate
Scientists have long known that
airborne mineral dust affects the climate. They know that darker, iron
oxide-rich substances absorb the Sun’s energy and warm the surrounding air,
while non-iron-based, brighter substances reflect light and heat, cooling the
air. Whether those effects have a net warming or cooling impact, however, has
remained uncertain.
Researchers have an idea of how
dust travels through the atmosphere, but the missing piece has been the
composition – the color, essentially – of the surface in the places dust
typically originates, which until now was derived from fewer than 5,000 sample
sites around the world. Based on billions of samples, EMIT’s maps offer much
more detail.
“We’ll take the new maps and put
them into our climate models,” said Natalie Mahowald, EMIT’s deputy principal
investigator and an Earth system scientist at Cornell University in Ithaca, New
York. “And from that, we’ll know what fraction of aerosols are absorbing heat
versus reflecting to a much greater extent than we have known in the past.”
Dust and
Ecosystems
Beyond harnessing EMIT’s mineral
data to improve Earth climate modeling, scientists can use the information to
study dust’s impact on the ecosystems where it lands. There’s strong evidence
that particles settling in the ocean can spur phytoplankton blooms, which can have implications for aquatic ecosystems and the planet’s
carbon cycle. Scientists also have shown that dust originating in the Andes of
South America, as well as in parts of northern and sub-Saharan Africa, provides
nutrients for
rainforest growth in the Amazon basin.
EMIT data can enable researchers to
pinpoint the sources of mineral dust and get a more detailed look at its
composition, helping estimate the travel of key elements such as phosphorus,
calcium, and potassium, which are thought to factor into this long-distance
fertilization.
“EMIT could help us to build more
intricate and finely resolved dust-transport models to track the movement of
those nutrients across long distances,” said Eric Slessarev, a soil researcher
at Yale University in New Haven, Connecticut. “That will help us to better
understand the chemistry of soils in places very far from the dust-generating
regions.”
A New
Generation of Science
Aside from tracking 10 key minerals
that are part of its primary mission, EMIT data is being used to identify a
range of other minerals, types of vegetation, snow and ice, and even
human-produced substances at or near Earth’s surface. And with vastly more
measurements at their disposal, researchers will be able to find statistical
relationships between surface characteristics and other features of interest.
For example, they might spot
signals in EMIT data that correspond with the presence of rare-earth elements
and lithium-bearing minerals, said Robert Green, a senior research scientist at
JPL and EMIT’s principal investigator. This new information could be used to
look for those substances in previously unknown places.
“To this point we simply haven’t
known the distribution of surface minerals over huge swaths of the planet,”
said Phil Brodrick, a JPL data scientist who spearheaded the creation of the
mineral maps. With the EMIT data, “there will likely be a new generation of
science that comes out that we don’t know about yet, and that’s a really cool
thing.”
More About the
Mission
EMIT was selected from the Earth
Venture Instrument-4 solicitation under the Earth Science Division of NASA’s
Science Mission Directorate and was developed at NASA’s Jet Propulsion
Laboratory, which is managed for the agency by Caltech in Pasadena, California.
The instrument’s data is available at the NASA Land Processes 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/
Source: NASA Sensor Produces First Global Maps of Surface Minerals in Arid Regions - NASA
No comments:
Post a Comment