CIRCULATION, HYDROGRAPHIC STRUCTURE AND MIXING AT TIDAL FRONTS - THE VIEW FROM GEORGES BANK

The steep slope on the northern side of Georges Bank and its location in the Fundy-Maine tidal system result in a persistent summertime fron tal system comprising a tidal-mixing front and a stratified tide-topog raphy interaction at the Bank edge. Recent field studies have provided a high-resolution description of the circulation, hydrographic struct ure and mixing in the region. Frontal features include an along-front residual jet, a surface convergence zone, regular variations in fronta l structure and position over the tidal period and tidal modulation cy cle, large-amplitude internal waves, and strong spatial and temporal v ariations in small-scale turbulence. The observations suggest that the magnitude of cross-front and vertical exchange in frontal regions can be site-specific depending on the relative importance of the underlyi ng physical processes.