The “Salt-Fountain” and Thermohaline Convection

A “gravitationally stable” stratification of salinity and temperature, such as is observed in the oceans, is actually unstable due to the fact that the molecular diffusivity of heat is much greater than the diffusivity of salt. We discuss this stability characteristic and the form of the convective motion in the laminar regime. Future studies of this model relative to the amplitude of the motion and the subsequent transition to turbulence should lead to the formulation of critical observational questions, which will determine whether the proposed mechanism is significant in the vertical mixing of the sea.