Aerosols are fine particles suspended in the atmosphere, significantly affecting weather and overall climate; they can control the absorption of solar radiation, determining the amount of thermal energy reaching the Earth.
On the other hand, aerosols contribute to increased cloud density. The sources of aerosols vary, including chimneys, construction sites, fires, factories, and others. They form in the atmosphere as a result of certain chemical reactions, such as nitrogen oxides and sulfur dioxide.
There were some complications regarding the monitoring of aerosols in urban areas specifically, and it is expected that they rise in urban areas compared to rural ones, which affects climate changes. However, there has not been enough interest in monitoring and observing aerosols at high altitudes, especially above urban areas, which is an important process to enhance our understanding of aerosols and their impacts.
And this is what an international research group has taken upon itself. They found that aerosol formation at high altitudes above urban areas was more pronounced, which helps provide a better understanding of the effects of aerosols on climate change. The researchers published their findings in the journal "One Earth" on January 17, 2025.
Beijing, the Chinese capital, is renowned for its towers, heights, and rich heritage. There, researchers used advanced measurement techniques on observation towers approximately 325 meters high and analyzed how aerosol particles form at different altitudes above urban areas.
Researchers discovered that while ground-level measurements yield valuable data, they fail to fully depict the formation of aerosol particles, particularly in densely populated urban areas such as Beijing in China, the world's second most populous city after India. This means that examining the atmosphere from high altitudes could also contribute to understanding atmospheric processes in urban environments.
The study also found that aerosol formation was stronger at higher elevations. They also discovered that higher concentrations of sulfuric acid and relative humidity make aerosol growth stronger in cities.
Researchers found the formation of new particles at different urban altitudes in Beijing, and these new particles are capable of enhancing cloud condensation nuclei at higher altitudes. It is worth noting that cloud condensation nuclei are small particles around which clouds gather, which is why they are sometimes referred to as "cloud seeds."
This study provides a deeper understanding of how aerosol and fine particles resulting from pollution and human activities interact and the implications of this for climate change. The more we understand something, the greater our ability to offer better solutions and innovations to mitigate and adapt to the impacts of climate change.
