What lies here like a light blue blanket over North Africa and the Middle East is atmospheric dust. It has an important cooling effect in the region.
As is known, greenhouse gases heat up the earth’s atmosphere. But they have opponents: dust particles. They can get into the atmosphere through human activities or naturally, for example when winds blow up desert dust. Such so-called aerosols are considered to be climate coolers because, among other things, they increase the cloud cover and thus ensure that more solar radiation is reflected back into space.
The conditions under which atmospheric dust unfolds its cooling effect and where this effect is particularly effective are still the subject of research. Georgiy Stenchikov from King Abdullah University in Thuwal and his colleagues have now devoted themselves to Saudi Arabia and the adjacent Red Sea. “Saudi Arabia is considered a dust belt and is responsible for around a third of the world’s dust emissions,” explains Stenchikov.
In their analysis of satellite data, the researchers found that atmospheric dust actually plays an important role in the region: the aerosols cool both the country and the Red Sea significantly. The amount of dust over the water is even greater than over the land area – the cooling effect is correspondingly strong. Nowhere else does dust develop such a great cooling effect over the ocean as over the southern Red Sea, according to the team.
Overall, the dust over the region helps to alleviate the extreme temperatures. Above the Red Sea, for example, this could help the heat-sensitive creatures living there: “The dust aerosols protect the coral reefs in the Red Sea,” says co-author Sergey Osipov from the Max Planck Institute for Chemistry in Mainz. In the future, the researchers want to further investigate the role of dust in the regional and global climate. Because only with this knowledge can climate models and forecasts become more reliable.