Compressible magnetoconvection in three dimensions: pattern formation in astrongly stratified layer

The interaction between magnetic fields and convection is interesting both because of its astrophysical importance and because the nonlinear Lorentz f orce leads to an especially rich variety of behaviour. We present several s ets of computational results for magnetoconvection in a square box, with pe riodic lateral boundary conditions, that show transitions from steady conve ction with an ordered planform through a regime with intermittent bursts to complicated spatiotemporal behaviour. The constraints imposed by the squar e lattice are relaxed as the aspect ratio is increased. In wide boxes we fi nd a new regime, in which regions with strong fields are separated from reg ions with vigorous convection. We show also how considerations of symmetry and associated group theory can be used to explain the nature of these tran sitions and the sequence in which the relevant bifurcations occur.