Atmospheric mixing state of soot related to water uptake, clouds, climate and health.

We have seen many signs of global warming over the last years, even though the cooling due to the direct and indirect effects of atmospheric aerosols has masked some of it. In contrast to other aerosols, soot particles also act warming by absorbing light.

A decrease in soot emissions due to their health effects or as actions against Short-live Climate Pollutants may continue the masking. The aerosol effects on the atmospheric radiation balance are still poorly understood.

This is especially the case for light absorbing soot particles and the cloud-albedo effect: the change in cloud albedo due to an increase in the cloud droplet number following an increase in the number of particles.

Fresh soot particles are initially not taking up water, but during ageing in the atmosphere water-soluble material will condense on them and eventually turn them into cloud condensation nuclei.We will study the water-uptake of soot particles by applying a novel combination of state of the art techniques.

This will give information about the mixing between soot and soluble aerosol compounds and to what degree soot can be involved in cloud droplet formation.

Our results will have relevance for the direct and indirect effect of soot particles on climate, human health and atmospheric lifetime of soot. We plan 2 field experiments in a forest area.

This work is a part of the strategic research area on climate modelling MERGE with direct connections to climate and Earth system modellers.