The aim of this colloquium is to bring together scientists from a range of disciplines (fluid mechanics, turbulence, atmospheric and oceanic sciences) to report on progress in understanding turbulent/nonturbulent interfaces, covering the following topics:

1. Turbulent-nonturbulent interfaces in boundary layers (e.g. jets, plumes, gravity currents, flames, oceanic mixed layer, atmospheric boundary layer): geometry, scaling, internal structure and dynamics;
2. Mixing and passive/active scalars at sharp interfaces, buoyancy effects;
3. Global intermittency in high-Reynolds number turbulence due to turbulent-nonturbulent transitions (stably stratified boundary layers, evolution of patches of turbulence);
4. Turbulent/non-turbulent interface models.

The multi-disciplinary and informal nature of the colloquium will give significant scope for cross-fertilisation.