For decades, scientists assumed that most global dust emissions came from the windswept deserts of North Africa. But the new analysis overturns this assumption.
Two studies published in JGR atmosphere And Holistic ecologyAssume that dust emissions vary by season and between hemispheres, and that the total amount of dust emissions worldwide is much lower than previously estimated.
Current models are outdated and have little to do with the reality on the ground, according to the international research team behind the study.
“When dust emission models were developed, there were only a few global data sets that were constantly changing and simplifying assumptions were made to apply them,” they wrote in the JGR Atmosphere paper. These simplifications include the assumptions that the Earth’s surface contains no vegetation, that most of the dust comes from North Africa and the Middle East, and that there are infinite amounts of dry, loose sediment on the surface.
In fact, researchers found that this is not the case. When they calculated calibrated annual dust emissions from 2001 to 2020 using daily satellite observations of dust emission sources every 500 meters across the Earth, the team found that much less dust was emitted to the surface than the model assumed.
The new analysis, published in the journal Science of the Total Environment, also found that Earth’s main dust source moves throughout the year between the deserts of East Asia, the Middle East and North Africa, and the scrublands of Australia and North America – a difference that is hidden by current models This. .
Dust in the atmosphere affects climate and human health, even in regions far from its source. Overall, the researchers wrote in the JGR Atmosphere study, the old models differed from satellite observations by up to two orders of magnitude.
“Current models only tell a small part of the story,” said Adrian Chappell, professor of climate change impacts at Cardiff University’s School of Earth and Environmental Sciences and lead author of both papers. he said in a press release.
Researchers warn that using old models risks delaying scientific progress and improving climate change predictions. They suggest that the field embrace new, more sensitive paradigms to encourage continued research.
2024-01-27 17:20:51
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