We study the formation of chemical patterns in reaction-diffusion systems for a Gray-Scott model system.

The following movies show how different chemical patterns evolve in a Gray-Scott reaction diffusion system for various choices of the reaction rate constant k and the feed rate F.

The movies were created by integrating the PDEs numerically with periodic boundary conditions on a spatial grid of 100x100 points. The the spatial variation of the concentration of (one of) the chemicals at a certain time is plotted as a pseudo-color plot. The colour of each square of the spatial grid is determined by the concentration of the chemical in this square. Finally the colours are interpolated to obtain a 'smooth' pattern. Since the patterns generally evolve rather slowly, the movies were compiled using only every 10th or 100th time frame, respectively. (This also reduces the file size of the resulting mpeg files enormously.)

• Blobs (u), Blobs (v)
• Loops (u), Loops (v)
• Stripes 1 (u), Stripes 1 (v)
• Stripes 2 (u), Stripes 2 (v)
• Stripes 3 (u), Stripes 3 (v)

Special thanks to the Mathematical Sciences Research Institute as well as the Computer science department at Cardiff university for giving me access to their computing facilities, and in particular to Frank Langbein (Computer Science, Cardiff University) for his technical assistance.