Vortex motion due to differential diffusion

Abstract

Convection caused by the double (differential) diffusion in a rotating medium can lead to a transfer of vorticity, and in particular, to its concentration. In geophysical applications, it is not considered usually, because the spatial and temporal scales of such convection and rotation effects differ greatly – the period of planetary rotation is many orders of magnitude greater than the characteristic time of existence of the corresponding convective structures in sea water. The paper draws attention to the fact that in the atmosphere there are possible the processes, in which a noticeable transfer of vorticity, caused by the difference in the effective exchange coefficients for various substances, seems to be more real. Effects of the type of double diffusion in the air are possible in principle, in connection with some difference in the rates of heat, water vapor and (or) heavy admixture transfer. The simplest linear model of convection due to double diffusion in a rotating medium is considered. The possibility of the contribution of such effects to the concentration of vorticity during the tornado formation is discussed.