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15 mins
Convective Ripening and Rainfall
Michael Wilkinson
Session: Atmospheric turbulence 3
Session starts: Wednesday 26 August, 10:30
Presentation starts: 11:45
Room: Room C

Michael Wilkinson (Open University)

This paper discusses the evolution of the droplet size distribution for a liquid-in-gas aerosol contained in a Rayleigh-B\'enard cell. It introduces a non-collisional model for broadening the droplet size distribution, termed \lq convective ripening'. The paper also considers the initiation of rainfall from ice-free cumulus clouds. It is argued that while collisional mechanisms cannot explain the production of rain from clouds with water droplet diameters of $20\ \mu {\rm m}$, the non-collisional convective ripening mechanism gives a much faster route to increasing the size of the small fraction of droplets that grow into raindrops.