DYNAMICS OF TIDAL MIXING FRONTS IN THE NORTH-SEA

Twenty years since the discovery of tidal mixing fronts there are stil l few convincing observations of the velocity field associated with th ese structures. Simple models of shelf sea fronts predict strong along -front jets, weaker convergent circulations and instabilities. ]During the North Sea Project a series of studies of the Flamborough frontal system has used a new approach based upon novel combinations of modern instrumentation (HF radar, acoustic Doppler current profiler, Decca-A rgos drifting buoys and towed undulating CTD) and have provided one of the first directly observed pictures of shelf sea frontal circulation . Observational confirmation of jet-like along-front flow has been fou nd together with evidence of cross-frontal convergence. A new generati on of eddy-resolving models will help to focus the next phase of front al circulation studies in relation to questions concerning baroclinic instability and eddy generation.