TOPOGRAPHICALLY INDUCED TURBULENCE ON CONTINENTAL SHELF OFF JOGASHIMA, SAGAMI BAY, JAPAN

Direct t urbulence measurements using TurboMAP over a “small ridge” on the continental shelf off Jogashima, Sagami Bay, Japan  reveal ed an active layer of topographically induced turbulence.  The active layer  ( = 10 -7 - 10 -6 Wkg -1 )  located at  mid-depth  of 200 – 250 m, occurred on alternate side of  “small ridge”depending on the direction of the tidal current.  This active layer wa s accompanied by rebounded-isopycnal surfaces 26.0 - 26.1 σ θ ,in which all in qualitative manner show ed an internal hydraulic flow control on the shelf. Th eturbulence friction velocitywa s two order of magnitude lower than observed- in this active layer explaining a less role of bottom friction than hydraulic flow to the high turbulence layer.Keywords: topographically induced turbulence, continental shelf, internal hydraulic flow