Steady Convective Exchange Flows Down Slopes Field and Laboratory Experiments

摘要

Horizontal exchange flows driven by destabilising surface buoyancy fluxes due to cooling are important in contributing to the transport of nutrients, micro-organisms and pollutants from littoral to pelagic zones in lakes and the coastal ocean. In particular we are interested in the magnitude of the discharge down a sloping bottom caused by destabilizing forcing fluxes. We develop scaling arguments to predict the dependency of this discharge upon the strength of surface forcing and the angle of the slope. From the discharge and the slope geometry we also predict the flushing timescale of the wedge. The predicted discharge rate agrees well with laboratory, field and numerical measurements covering a wide range of parameters.