Researchers from the University of California Los Angeles (UCLA) have discovered the Earth has four times as much coarse dust in its atmosphere than currently simulated by climate models.
As one of the main components to the Earth’s climate, dust plays a major role in affecting the planet’s weather conditions and living organisms.
And while most quarrying and extractive industry workers can identify the dangers of fine dust particles, the amount of coarse dust on the planet — which originates in areas such as the Sahara Desert — has been shown to have a higher abundancy than previously expected.
Coarse dust warms the atmosphere, with the particles being much larger than those found in fine dust, which instead cools the earth by scattering sunlight in a similar way to clouds.
New research from UCLA scientists published in the Science Advances journal found that the Earth’s atmosphere contains 17 million tonnes of coarse dust – four times above previously recorded levels on climate models.
The researchers made the dusty discovery after taking over two dozen measurements of coarse dust fractions at different locations, heights and seasons. The report noted other global models of dust measurements underestimate the importance of coarse dust at these different measurements.
According to one of the study’s authors, UCLA department of atmospheric and oceanic sciences postdoctoral researcher Adeyemi Adebiyi, climate models need to focus on coarse dust.
“Coarse mineral dust is an important component of the Earth system that affects clouds, ocean ecosystems, and climate,” he said.
By focusing on the missing coarse dust in climate models, Adebiyi said it increases the possibility that both fine and coarse dust is heating up the Earth’s climate system.
Adebiyi completed the study with UCLA associated professor of atmospheric and oceanic sciences Jasper Kok by analysing a multitude of air-craft based observations, including measurements of dust taken over the Sahara Desert.
“When we compared our results with what is predicted by current climate models, we found a drastic difference,” Kok said.
The study also revealed dust particles travel thousands of miles in the atmosphere, with dust in the Sahara reaching the United States. Additionally, if dust from the desert lands in the oceans, it can increase carbon dioxide absorption in the sea.
“To properly represent the impact of dust as a whole on the Earth system, climate models must include an accurate treatment of coarse dust in the atmosphere,” Adebiyi said.