The cross-sectional structure of the ASF is provided by 26 closely spaced (about 3 km) conductivity-temperature-depth (CTD) profiles, taken across the Eastern Weddell Sea continental shelf break at 17°W (Nøst and Lothe, 1997), and referred to as the NARE section hereafter. The section of potential temperature from these data (Fig. 3(a)) shows a southward deepening thermocline that intersects the continental shelf at about 600 m depth, separating the ESW and WDW. The difference between the two water masses is also seen in the potential temperature-salinity (θθ–S) diagram in Fig. 3(b). In this figure, ESW with temperatures near the surface freezing point (about −1.9 °C) and WDW with temperatures

of +0.9 °C appear as two endpoints joined by a straight line. This mixing product of the ASF pycnocline is known Selleck MI-773 as Modified Warm Deep Water (MWDW). Being collected during the austral summer, the NARE section also illustrates the properties of the fresh,

near surface ASW, which is the most buoyant water mass with temperatures of up to −1 °C in Fig. 3(b). In addition, a set of more than 2000 CTD profiles collected by instruments affixed to southern elephant seals, presented by Nøst et al. (2011) and referred to as seal data hereafter, gives a unique sample of the seasonal evolution of the water masses Selleckchem SP600125 along the coast. The seal data and the NARE section are combined to construct a time-dependent version of the ASF cross-section. In this construction, water mass properties below the thermocline, here defined as the 0.3 °C isotherm,

are given by the NARE section and remain constant in time. The upper-ocean properties are provided by a time series of the horizontally averaged seal data. To assure a smooth transition between the two datasets, the hydrographic properties at the vertical interface have been interpolated over a constant thermocline thickness of 70 m, obtained by analyzing the seal data, and with corrections ifoxetine applied to preserve realistic properties of the MWDW. The resulting depth/time section of upper ocean salinity in Fig. 3(c) reveals a pattern of summertime near-surface freshening, followed by a vertical homogenization due to the salinification from brine rejection during sea ice formation in winter. The NARE section prescribing deep ocean properties in our climatology is located several hundred kilometers west of our study region. However, a comparison with both the CTD profiles taken near the FIS, and with the seal data, shows that the assumption of constant deep ocean properties along the Eastern Weddell Sea coast is a reasonable first-order approximation for our process-oriented model setup. The main driver of the mean circulation along the Eastern Weddell Sea coast is the mechanical surface forcing due to prevailing easterly winds (Nunez-Riboni and Fahrbach, 2009).