A dust plume stretches over the eastern Mediterranean, shrouding parts of
Greece, Turkey, and Cyprus. The June 2020 image has been cropped and enhanced
to improve contrast, and lens artifacts have been removed. NASA’s EMIT mission
will help scientists better understand how airborne dust affects climate. Credits:
NASA
Designed to analyze airborne dust to see how it might affect climate, the EMIT mission launches to the International Space Station on Thursday, July 14.
Each year, strong winds carry more than a
billion metric tons – or the weight of 10,000 aircraft carriers – of mineral
dust from Earth’s deserts and other dry regions through the atmosphere. While
scientists know that the dust affects the environment and climate, they don’t
have enough data to determine, in detail, what those effects are or may be in
the future – at least not yet.
Set to launch to the International Space Station
aboard a SpaceX Dragon spacecraft on Thursday, July 14, at 8:44 p.m. EDT (5:44
p.m. PDT), NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) instrument will help fill in those
knowledge gaps. EMIT’s state-of-the-art imaging spectrometer, developed by the
agency’s Jet Propulsion Laboratory in Southern California, will collect more
than a billion dust-source-composition measurements around the globe over the
course of a year – and in doing so, significantly advance scientists’
understanding of dust’s influence across the Earth system.
Live coverage from NASA’s Kennedy Space Center in
Florida will air on NASA Television, the NASA app, and the agency’s website. Prelaunch events on Wednesday, July 13, include a 2
p.m. EDT (11 a.m. PDT) climate conversation on NASA TV with Kate Calvin, NASA’s
chief scientist and climate advisor, and Robert Green, EMIT’s principal
investigator at JPL.
Teachable Moment: Learn More
About NASA’s Mission to Study Dust in Earth’s Atmosphere
Here are five things to know about EMIT:
1. It
will identify the composition of mineral dust from Earth’s arid regions.
Desert regions produce most of the mineral
dust that makes its way into the atmosphere. They’re also largely remote,
making it difficult for scientists to collect soil and dust samples over these
vast areas by hand.
From its perch on the space station, EMIT will map the world’s mineral dust source regions. The imaging spectrometer will also provide information on the color and composition of dust sources globally for the first time. This data will help scientists understand which kinds of dust dominate each region and advance their understanding of dust’s impact on climate and the Earth system today and in the future.
Using image spectrometer technology developed at JPL, NASA’s EMIT mission
will map the surface composition of minerals in Earth’s dust-producing regions,
helping climate scientists better understand the impact of airborne dust
particles in heating and cooling the planet’s atmosphere. Credits:
NASA/JPL-Caltech
2. It will clarify whether mineral dust heats or cools the planet.
Right now, scientists don’t know whether mineral dust has a cumulative
heating or cooling effect on the planet. That’s because dust particles in the
atmosphere have different properties. For instance, some particles may be dark
red, while others may be white.
The color matters because it determines whether the dust will absorb the
Sun’s energy, as dark-colored minerals do, or reflect it, as light-colored
minerals do. If more of the dust absorbs the Sun’s energy than reflects it,
it’ll warm the planet, and vice versa.
EMIT will provide a detailed picture of how much dust comes from dark
versus light minerals. That information will allow scientists to determine
whether dust heats or cools the planet overall, as well as regionally and
locally.
3. It will help scientists understand how dust affects different Earth
processes.
Mineral dust particles vary in color because they’re made of different
substances. Dark red mineral dust gets its color from iron, for example. The
composition of dust particles affects how they interact with many of Earth’s
natural processes.
For instance, mineral dust plays a role in cloud formation and atmospheric chemistry. When mineral dust is deposited in the ocean or forests, it can provide nutrients for growth, acting like fertilizer. When it falls on snow or ice, the dust accelerates melting, leading to more water runoff. And for humans, mineral dust can be a health hazard when inhaled.
As depicted in this illustration, NASA’s EMIT will be attached to Express
Logistics Carrier 1, a platform on the International Space Station that
supports external science instruments. The mission will help scientists better
understand the role of airborne dust in heating and cooling the atmosphere. Credits:
NASA/JPL-Caltech
EMIT will collect information on 10 important dust varieties, including
those that contain iron oxides, clays, and carbonates. With this data,
scientists will be able to assess precisely what effects mineral dust has on
different ecosystems and processes.
4. Its data will improve the accuracy of climate models.
In the absence of more specific data, scientists currently characterize
mineral dust in climate models as yellow – a general average of dark and light.
Because of this, the effects that mineral dust may have on climate – and that
climate may have on mineral dust – are not well represented in computer models.
Color and composition information gathered by EMIT will change that. When
the instrument’s data is incorporated, the accuracy of climate models is
expected to improve.
5. It will help scientists predict how future climate scenarios will affect
the type and amount of dust in our atmosphere.
As global temperatures rise, arid regions may become even drier, possibly
resulting in larger (and dustier) deserts. To what extent this might happen
depends on several factors, including how much temperatures rise, how land use
changes, and how rainfall trends change.
By incorporating EMIT’s global dust source composition data into models and
predictions, scientists will gain a better understanding of how the amount and
composition of dust in arid regions may change under different climate and
land-use scenarios. They’ll also gain a better understanding of how these
changes may impact climate in the future.
More About the Mission
EMIT was developed at NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California. It will launch from Kennedy Space Center in Florida to the International Space Station aboard SpaceX’s 25th commercial resupply services mission for NASA. Once EMIT begins operation, its data will be delivered to the NASA Land Processes Distributed Active Archive Center (DAAC) for use by other researchers and the public.
To learn more about the mission, visit: https://earth.jpl.nasa.gov/emit/
Source: NASA’s
New Mineral Dust Detector Readies for Launch | NASA
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