Spatial bistability of two-dimensional turing patterns in a reaction-diffusion system

A Turing bifurcation from an uniform state to a striped patterned state was observed in experiments conducted in a single-phase spatial open gel reactor with the chlorite-iodide-malonic acid-starch (CIMA) reaction; previous experiments had revealed a bifurcation from a uniform state to hexagons rather than stripes. A modified reactor is used to demonstrate that the hexagonal and striped patterns are quasi-two-dimensional; this is further confirmed by a direct measurement of the third dimension of patterns with a camera of high resolution in depth of field. For some range of chemical concentrations the hexagonal and striped patterns are bistable; this is the first evidence of spatial bistability between Turing structures. 24 refs., 5 tabs.