The dynamics of $A+B\to C$ fronts in horizontal solution layers can be influenced by buoyancy-driven convection as soon as the densities of $A$, $B$, and $C$ are not all identical. Such convective motions can lead to front propagation even in the case of equal diffusion coefficients and initial concentration of reactants for which reaction-diffusion (RD) scalings predict a nonmoving front. We show theoretically that the dynamics in the presence of convection can in that case be predicted solely on the basis of the knowledge of the one-dimensional RD density profile across the front.

• Received 27 March 2008

DOI:https://doi.org/10.1103/PhysRevLett.101.084503