Darker, iron-rich dust would absorb the Sun’s heat and warm the surrounding air, while lighter, clay-rich particles would do the opposite. “Different dusts have different properties — they’re acidic, they’re basic, they’re light, they’re dark — that determine how the particles interact with the Earth’s atmosphere, as well as the soil, water and Robert O. Green, EMIT principal investigator and longtime researcher at NASA’s Jet Propulsion Laboratory in Southern California. With the EMIT data, he added, “we’ll be on the lookout to map dust source regions around the world and understand how dust heats and cools the planet, and how that might change over time.” future climate scenarios.”
Researchers at NASA and others have long focused on dust flight – a journey that can last for hours or weeks, depending on particle size. Its atmospheric effects are included in climate models, but it remains unclear whether the dust has a warming or cooling effect on the planet and how this is changing over time.
Natalie Mahowald, EMIT’s deputy principal investigator and Earth systems scientist at Cornell University in Ithaca, New York, said the uncertainty comes from the lack of data on dust composition. The knowledge the researchers gained came from fewer than 5,000 sampling sites, most of which are located in farming areas where detailed information about the soil could be used for agricultural purposes or Commerce. Because few crops grow in deserts, dust-producing areas of the world tend to be unsampled, so the scientists had to assume the dust composition in their computer simulations, combining land, water, and air data for climate change modeling.
“Usually in climate models we model dust as yellow – the average color of all dust – but if you’ve ever been to a desert region, you know that sand isn’t just one color,” said Mahowald. “So assuming it’s globally uniform doesn’t reflect what’s happening in reality.”
