High-resolution observations of the path of the overflow from the Sicily Strait

High-resolution velocity and hydrographic measurements, including data acquired by the autonomous underwater vehicle AUTOSUB-2, are used to provide a detailed description of the path of the deep and intermediate overflow waters in the north-west region of the Sicily Strait. There are two branches of the overflow: one passing through the western sill and the other passing through the eastern sill. The western branch of the overflow is seen to circulate around the central bank separating the two sills and head back towards the eastern Mediterranean before turning northwards again. It then follows a path similar to that of the eastern branch but at a deeper level. Although weak, the western branch is still identifiable 60 km downstream of the sills and lies below the eastern branch of the overflow. The net transport is estimated to be 1 Sv which is consistent with other studies. Evidence of tidal and sub-tidal variability in the overflow is also presented.