Atmospheric aerosols slow down climate change, but we still don't know exactly how much. One of the major reasons behind the uncertainty is the difficulty to separate the effect of anthropogenic aerosols on clouds from natural background. Therefore, the aim of this project is to solve how biogenic secondary organic aerosols (BSOA) affect clouds over boreal forests. We will use field observations of aerosols and satellite observations of clouds together with large eddy simulations, meteorological reanalysis data and climate model simulations. To identify the BSOA contribution on cloud properties we will use neural networks. First, we will develop these methods for Southern Finland and then extend the analysis to other boreal areas to estimate the radiative effects of BSOA in present day climate. The project will produce unprecedented information on how BSOA affects cloud properties. This is urgently needed information for the separation of natural and anthropogenic aerosol effects.

2021

2026