Soret effects on the onset of convection in rotating porous layers via the "auxiliary system method"

The onset of convection in a ternary horizontal porous fluid layer, heated from below and salted from above and below, in the presence of Soret thermo-diffusive effects (in the Darcy-Boussinesq scheme) is investigated. Via a new approach ("auxiliary system method"), it is shown that do not exist subcritical instabilities and that the global nonlinear stability is guaranteed by the linear stability. The Soret stabilizing-destabilizing effects, via algebraic conditions in closed forms, are obtained also discovering symmetries and skew-symmetries hidden in the Darcy-Boussinesq equations.