Two-dimensional oscillations in MHD Rayleigh-Benard convection

Short-period oscillations on convection rolls in Rayleigh-Bénard convection affected by a horizontal magnetic field confined in moderate aspect ratio box were invested experimentally. Detailed measurements of temperature and velocity fluctuations corresponding to the oscillations elucidated that the oscillation around its onset is two dimensional and may be originated in absolute instability of recirculation vortices formed flow separations due to large inertia of the main convection rolls restricted by Lorenz force.