Published in Atmospheric Chemistry and Physics, this study focuses on understanding how biomass burning plumes influence the behaviour of stratocumulus clouds over the southeast Atlantic region during the period of intense fires in southern Africa. The team of researchers, among them being FORCeS participants Frida Bender, Matthias Schwarz, Juha Tonttila, Harri Kokkola, and Annica Ekman, used a sophisticated modelling technique called large-eddy simulation to delve into the complex interplay between aerosols and moisture in shaping cloud dynamics.
Their investigation reveals that certain factors, such as sea surface temperatures and the mixing of air at cloud tops, play pivotal roles in determining how these clouds evolve. Interestingly, they find that while aerosols have limited indirect effects on cloud behaviour, their ability to absorb sunlight can significantly alter cloud cover. In areas heavily polluted by aerosols, this effect becomes particularly pronounced, causing clouds to dissipate more quickly and transition into cumulus formations.
Moreover, the researchers uncover the cooling influence of moisture accompanying the aerosol-laden plumes. This additional factor helps to mitigate some of the warming effects induced by aerosol absorption of solar radiation, adding nuance to our understanding of the complex atmospheric processes at play.
Despite these insights, the study underscores the persistent uncertainty surrounding the intricate interactions between biomass burning aerosols, clouds, and radiation. To gain a more comprehensive understanding, the researchers advocate for continued collaborative efforts involving different modelling approaches and in situ observations. Such endeavours are crucial for refining our understanding of this complex system and its broader implications for climate dynamics.
Access the publication here: https://acp.copernicus.org/articles/24/4591/2024/
