Analytical Model of Shear Flow over a Thermally Heterogeneous Surface
摘要
As is well known, one of the most important factors in the development of dangerous convective phenomena in the atmosphere is the vertical shear of the background wind speed. Therefore, the problems of theoretically describing the interaction of convection and thermal circulations with a shear flow are very relevant. A linear stationary problem of the interaction between a horizontal flow with a vertical shear and thermal circulations (density currents) existing over a thermally inhomogeneous horizontal surface is considered. It is assumed that, in the absence of thermal inhomogeneities, there is a background flow with a constant vertical shear of velocity (Couette flow) in a stably stratified medium. Stationary disturbances caused by thermal inhomogeneities of the underlying surface, extended along the background flow, are studied. Thus, a linear stationary two-dimensional problem is considered in the Boussinesq approximation. Coriolis accelerations are not taken into account, since relatively small horizontal scales of inhomogeneities are assumed. The consideration is limited to one horizontal harmonic of disturbances. One essential dimensionless determining parameter is an analogue of the Rayleigh number