A nonlinear bifurcation in cellular convection theory.

Time dependent solutions of the nonlinear modal equations for cellular convection in a fluid layer heated below have demonstrated the existence of a nonlinear bifurcation which leads to a stable regime with reduced heat flux and vertical velocities. This new state is brought about by the growth, to a significant level, of the vertical component of vorticity after an initial quasi-steady state has been established. The growth rate mechanism has been investigated analytically and compared with the numerical results. These vorticity modified solutions exhibit favourable features which could be established in the solar convection zone.