Cloud-aerosol-turbulence interactions: Science priorities and concepts for a large-scale laboratory facility

Clouds and aerosols, ubiquitously embedded in turbulent flows, are central to the prediction of weather and climate. The purpose of the workshop described here was to explore scientific questions and set priorities for a large-scale aerosol–cloud–turbulence laboratory facility. (Here, "facility" denotes one or more aerosol/cloud chambers and the associated instrumentation and technical/scientific staff.) Specifically, at the workshop we attempted to gauge community interest and to obtain a sense of priorities for the scientific challenges likely to be amenable to laboratory investigation. The two overarching questions guiding the workshop presentations and discussion were as follows: What pressing scientific questions can we answer with a large-scale aerosol–cloud–turbulence facility that would be difficult or impossible to address otherwise? What would a large-scale aerosol–cloud–turbulence facility look like and what measurement capabilities should be associated with it? The purpose of this meeting summary, therefore, is to outline the range of scientific questions, and the facility concepts that were explored. We began the workshop with a series of overview talks to highlight scientific questions that could be investigated in a large-scale aerosol–cloud–turbulence laboratory facility. Topics included warm and mixed-phase cloud microphysics, aerosol and cloud chemistry, atmospheric turbulence, radiative transfer, cloud/aerosol instrumentation, and remote sensing. There was ample time for questions and discussion following each overview presentation. We also broke into groups for several hours at various points to enable more active discussion among all participants.