Do Near-Boundary Processes Control the Ocean?

Three ways in which near-boundary processes influence the ocean are reviewed. In the first topic, solutions for the flow and stratification in a situation where mixing dies away slowly away from a sloping boundary can show a sensitivity to the eddy Prandtl number, emphasizing the importance of studying the mixing of momentum as well as buoyancy. In the second topic, the importance of near-boundary mixing in the deep Canada Basin is suggested by the presence in the basin interior of a thermohaline staircase that appears not to be able to account for the vertical heat flux and is also disrupted near the sloping sides by what appears to be a region of strong mixing. The third part of the paper is a summary of some simple recent advances in hydraulic theory that may be relevant to the dynamics and influence of oceanic overflows.