%0 Journal Article %A Díaz Díaz, Jesús Ildefonso %A Rakotoson, Jean Michel Theresien %A Schmidt, Paul G. %T A parabolic system involving a quadratic gradient term related to the Boussinesq approximation %D 2007 %@ 1578-7303 %U https://hdl.handle.net/20.500.14352/49944 %X We propose a modification of the classical Boussinesq approximation for buoyancy-driven flows of viscous, incompressible fluids in situations where viscous heating cannot be neglected. This modification is motivated by unresolved issues regarding the global solvability of the original system. A very simple model problem leads to a coupled system of two parabolic equations with a source term involving the square of the gradient of one of the unknowns. Based on adequate notions of weak and strong solutions, we establish the global-in-time existence of weak solutions and the uniqueness of strong solutions. %~