  In this article, we present a bifurcation analysis on the double-diffusive
convection. Two pattern selections, rectangles and squares, are investigated.
It is proved that there are two different types of attractor bifurcations
depending on the thermal and salinity Rayleigh numbers for each pattern. The
analysis is based on a newly developed attractor bifurcation theory, together
with eigen-analysis and the center manifold reductions.
