The impact of aerosol particles from anthropogenic and natural sources on clouds and cloud effects on aerosol is a large source of uncertainty in our ability to predict the present climate. It is a multifaceted problem that necessitates laboratory studies, observations in the ambient atmosphere and model simulations from the molecular scale to the global scale. This workshop will bring together new avenues of work by scientists in this field with complementary backgrounds including but not limited to: cloud microphysics and dynamics, ice nucleation, aerosol activation, and aerosol chemistry and microphysics. In each of these areas we strive to bring together experimentalists and modellers. The schedule will be coordinated to allow for exploring connections amongst all participants.