Clouds play a crucial role in regulating the Earth's temperature and climate, and their formation is a complex process involving the interaction of various atmospheric gases. In particular, the formation of cloud droplets requires the presence of tiny particles, known as cloud condensation nuclei (CCN), on which water vapor can condense.
In the atmosphere, CCN can come from different sources, including aerosols emitted by natural processes, such as forest emissions, and human activities, such as industry and traffic.
The CLOUD experiment is designed to study the formation and properties of clouds in a controlled laboratory environment. The experiment uses a large vacuum chamber to simulate atmospheric conditions and allows researchers to investigate the effects of different gases and particles on cloud formation.
In the latest results, published in the journal Nature, the CLOUD team investigated the effect of emissions from boreal forests on cloud formation. These emissions include organic compounds such as terpenes and isoprene, which are released into the atmosphere from trees.
The researchers found that these biogenic emissions can enhance cloud formation, particularly in clean air environments where the concentration of other CCN is low. They showed that the effect is comparable to that of emissions from human activities, such as sulfate aerosols from industry.
The findings suggest that natural emissions from forests play an important role in regulating cloud formation and climate, and that these effects need to be considered in climate models.
Citation: Kirkby, J., et al. (2023). Biogenic influences on cloud microphysics. Nature, 613(7942), 253-259.
