Clustering of particles driven by salinity gradients in turbulence

Experimental analysis of the diffusiophoretic effect in turbulence demonstrates that preferential concentration of particles driven by the combined action of turbulence and inhomogeneous distribution of salinity exists. Additionally, theoretical predictions on the distribution of diffusiophoretic particles could be confirmed. We provide evidence that inhomogeneous salt distributions in turbulence produce particle clustering in fractal sets at scales below the Kolmogorov scale. This clustering mechanism may provide the key to understanding a multitude of processes such as formation of marine snow in the ocean and population dynamics of chemotactic bacteria.