Page 24 - UNEP_MAP2015

variability to the flow of the MAW into the Ionian Sea.
The path of the MAW is more complicated in winter than in summer. The analysis of the
climatological buoyancy fields which actually indicate an intensification of the flow on the
southern side of the channel during autumn and spring, whereas the flow is concentrated
against the Sicilian side, reaching a salinity of 38.77.
The ATC feeds the circulation into the Gulf of Hammamet, where a cyclonic recirculation has
been identified at 40 m depth. In summer, the waters of the Gulf of Hammamet are thus
regenerated by the Atlantic water vein. In winter, the apparent convergence of surface waters
towards the coasts of the Gulf as well as the flowing towards the South East of bottom
waters suggest the establishment of a vertical agitation during this season.
North of the Lampedusa island, the Atlantic current splits in two branches: the first one
towards the south-east and the second towards the south, feeding the circulation along the
Gulf of Gabes. The flux presents a wellmarked seasonal variability (Manzella et al., 1988).
The intensity of the second branch is consequently subject to fluctuations directly affecting
local cyclonic circulation. The Gulf of Gabes occupies a vast region of shallow waters which
are in thermal contrast with the waters from deeper regions in the east of the plateau. In
these deeper regions the localisation of fronts corresponds to a bathymetric contour equal to
the depth of the mixed water (40 to 50 metres).

21