A Schlieren optical setup allows the direct visualisation of gradients in chemical composition or temperature. It has been used for instance to measure the influence of chemical reactions on CO2 sequestration.

Example Image

A snapshot of the plumes developing below the interface when gaseous CO2 dissolves in a 0.1mol KOH solution. More information can be found here:

Example Image

Visualisation of ice growth in saline water shows instabilities induced by the rejection of brine of the growing ice layer. More information can be found here: