(CNN) In the Mediterranean, it is called “.Sirocco,” and in the Canary Islands, “the fog“when it goes”harmatton“In West Africa, and”Habob“In Sudan. But all these different names describe the same thing: dust storms.
Sand and dust storms are a global phenomenon. These fine dust particles can be carried by wind Thousands of milesAffecting health and livelihood.
According to UNDust storms have increased dramatically in recent years due to climate change, land degradation and drought.
Climate scientist Natalie Mahowald By learning more about dust storms, he hopes to plan for the future. A professor of engineering at Cornell University in the US, he has been monitoring dust around the world for the past two decades — and is now working with NASA on a new instrument called EMIT.
The first type, a space-borne imaging spectrometer, helps map dust colors. Scientists can use the data in their climate models to figure out how different minerals warm or cool the planet, Mahowald explains. Each type of dust has its own unique light-reflectance signature: For example, white dust reflects solar radiation or heat, while “red and dark dust absorb it,” he says.
EMIT (Earth Surface Mineral Dust Source Survey) “will revolutionize what we can do,” says Mahowald. “We can use it (the data) to better understand what the impact of desert dust is.”
A mineral map
Launched in July 2022, EMIT is attached to the International Space Station and orbits Earth 16 times a day, collecting data to map the mineral composition of the planet’s surface. SpectrumDifferent wavelengths of light emitted by different colors.
This information allows researchers to determine the mineral and chemical composition of materials on the surface. Scanning 50-mile-wide strips in seconds, the gadget will provide scientists with billions of data points to use in climate model predictions — vastly expanding the current data set. 5,000 sample sitesMahowald says.
Much of the data for which detailed soil information is valuable for agricultural and commercial purposes comes from agricultural land. The wealth of information provided by EMIT, which includes data from the world’s driest regions, will help scientists learn more about dust and its impact on climate — an issue Mahowald says has been largely overlooked until now.
A vicious cycle
The UN estimates that 2,000 million tons of sand and dust are released into the atmosphere annually.
Sand and dust storms are essential to the planet, carrying them Nutrient soil Across countries and continents and helps plant life flourish – dust from the Sahara desert, for example Feeds on trees in the Amazon rainforestWhere the soil lacks the necessary nutrients.
“The ecosystem really relies on dust aerosols,” said Diana Francis, a climate scientist at Khalifa University in Abu Dhabi.
But if dust storms become more frequent and intense, they can accelerate global warming: A UN report highlights Changing storm patterns can alter the distribution of Earth’s minerals and reduce rainfall, while dust aerosols can act like greenhouse gases in the atmosphere by absorbing solar radiation.
This can create a feedback loop in which climate change causes more intense dust storms Land degradation and drought, and dust storms exacerbate climate change. There is evidence of this already happening, Francis says, pointing to the “Godzilla” dust storm that is the world’s largest. 20 yearsIt crossed the Atlantic in June 2020, darkening skies from the Caribbean to the US state of Texas.
Dust storms can cause respiratory diseases, damage livestock and crops and disrupt traffic. In the Middle East and North Africa region, they are estimated to cost the economy $13 billion per year.
And the number and intensity of storms in the Sahara desert is increasing, says Francis. In some of his earlier research, he found that changes in atmospheric circulation caused dust from the Sahara to reach the Arctic.
“Over the past two decades, we’ve noticed a significant darkening of the ice in the Arctic,” Francis said, highlighting another feedback loop. “When ice is dark it reflects sunlight less, so we know it will melt faster.”
More than just dust
EMIT has so far provided 5,000 data sets — each containing 1.4 million spectra. NASA scientists use the data to map the composition of dust and soil around the world.
But EMIT’s data is used to map another factor influencing climate change: Methane.
Although it makes up only a fraction of greenhouse gas emissions, methane is estimated to be present 80 times More warming power than carbon dioxide in the first 20 years of entering the atmosphere.
Methane absorbs infrared light in a unique form, “Spectral fingerprintingEMIT can be precisely pinpointed by an imaging spectrometer. Although NASA knew EMIT’s imaging technology could detect greenhouse gas emissions, it “performed better than expected,” says Robert Green, senior research scientist and principal investigator at NASA’s Jet Propulsion Laboratory. EMIT task.
So far, EMIT has detected 50″.Super-emitters“Across the world, it comes mostly from fossil fuel, waste and agricultural facilities in places including the United States, Iran and Turkmenistan.
While carbon dioxide persists in the atmosphere for centuries, methane dissipates after a decade, ie Reducing methane emissions is the quickest way to mitigate climate change. NASA hopes this information will encourage countries to curb methane emissions.
Although EMIT’s work was initially planned to last only 12 months, Green says there are now plans to extend the project.
Mahowald is excited for the future. “The EMIT project is testing the waters and showing what’s really possible,” he says. “We’re going to go from 5,000 to billions of data, and much higher resolution. That’s going to help us tremendously.”
