Called EMIT, the Earth Surface Mineral Dust Source Investigation will analyze dust carried through the atmosphere from dry regions
to see what effects it has on the planet.
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.
Launching to the International Space Station on June 9, 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.
Here are five things to know about EMIT:
- 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, EMIT 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 Earth’s atmosphere. Credits: NASA/JPL-Caltech
2.
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.
- It will help scientists understand how dust affects different Earth processes.
Officials from NASA and JPL oversee vibration testing of the EMIT science
instrument, including its telescope and imaging spectrometer. Credits:
NASA/JPL-Caltech
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.
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.
- 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.
- 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 dryer, 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 is being 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: 5 Things to Know About NASA’s New Mineral Dust Detector | NASA
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