Aerosol-cloud interactions over the boreal forest

Speaker: Liine HEIKKINEN (ACES Team, Department of Environmental Sciences) – Working on atmospheric sciences (Life cycle and impact of aerosols in indoor and outdoor air)

Date: Wednesday, December 13, 2023 at 1:30 PM

Location: OSU-Réunion room

Seminar summary:

The presentation focuses on the complex dynamics of aerosol-cloud interactions, with particular emphasis on the challenges they pose for climate models. The study is centered on the boreal forest environment, which constitutes around 29% of the world’s forested areas and is recognized for its significant role as a natural source of aerosol particles. As the concentration of anthropogenic aerosol particles decreases due to air quality improvement measures, natural aerosol emissions play an increasingly important role as “seeds” (condensation nuclei) for cloud droplets. The abundance of these particles is becoming an important factor influencing cloud properties, in particular droplet concentration.

During the presentation, Liine will discuss the impact of environmental conditions on natural aerosol concentrations in the boreal forest. She will show the co-variation of these concentrations with observed cloud properties over the forest, and examine the extent to which climate models account for the observed relationships. Finally, the presentation will address the influence of trace gases emitted by the forest on cloud properties via co-condensation, a process currently omitted from climate models. It will also present new, simple methods for assessing the impact of cloud water chemistry on aerosol chemistry.