A BOUNDARY CURRENT-INDUCED BY DIFFUSION N EAR A MOTIONLESS HORIZONTALCYLINDER IN CONTINUOUSLY STRATIFIED FIELD

The Cauchy problem of the formation of a diffusion-induced boundary la yer near a motionless horizontal cylinder in a continuously stratified fluid at rest is solved in the Boussinesq approximation. Asymptotics of the tangential and radial velocities and of the salinity perturbati on for short periods are obtained using the Laplace transformation, an d conditions of their applicability are determined. The boundary curre nt under formation splits into two sublayers (the velocity and density sublayers) of considerably different thicknesses. The ratio between t hicknesses of these layers is independent of time and is determined by the ratio between the diffusivity and the kinematic viscosity of flui d. Expressions for the circulation and the dynamic vorticity are also obtained, The asymptotic expressions obtained turn to known asymptotic solutions consistent with the exact solution of the nonstationary pro blem of a sloping plane.