Laboratory experiments of particle-driven convection

Particle-driven convection occurs when a dense particle-laden layer settles into a layer of clear fluid. This can drive a variation on the classical Rayleigh-Taylor instability, where particles induce the density difference between the two fluids. Variants of this instability occur in many geophysical flows, such as the undersides of volcanic ash clouds, sediment-laden river outflows, and the dynamics of droplets in clouds. This talk will present some new experimental results of Rayleigh-Taylor instability occurring between a particle-laden and fresh-water layers. We will also present some preliminary results that examine the effect of adding salt to the lower layer. For this second case, the initial stratification is stable, but becomes unstable due to particle settling.