3 July 2012Jonathan Reid, David Bones and collaborators from ETH-Zurich have shown that the rate of condensation of water on organic aerosol particles in the atmosphere can be very slow, taking many hours for a particle to change in size. This could have significant consequences for understanding how clouds are formed, affecting climate.
Cloud droplet growth can be dependent on the composition of particles less than 1 micrometre in diameter
The research found that for aerosol particles with high viscosity water evaporation and condensation can take many hours, for less viscous particles evaporation and condensation can be very fast - less than 1 second. These rates influence the cloud reflectivity and lifetime.
Dr Reid said: "Although not providing all the answers, this work helps us better understand the 'known unknowns'. Most importantly, it demonstrates that better understanding the rate at which water condenses on particles in the atmosphere is crucial for understanding clouds".
The research was funded by the Engineering and Physical Sciences Research Council (EPSRC) UK.
The findings have been published in the Proceedings of the National Academy of Sciences. 'Comparing the mechanism of water condensation and evaporation in glassy aerosol' by David Bones, Jonathan Reid, Daniel Lienhard and Ulrich Krieger.