Dense water masses form on the Arctic and Antarctic shelves through cooling and rejection of salt during sea-ice growth. Deep and bottom water in the world can be explained partly by subsequent shelf convection. Large-scale lateral advection from the adjoining continental shelves also maintains the cold upper halocline of the Arctic Ocean. Hence, the brine-enriched waters cascading off the continental shelves are crucial for the global ocean circulation and climate. The Norwegian Atlantic Current brings warm and saline water to the Barents Sea. The transported heat is effectively lost through intense atmosphere–ocean heat exchange. The Barents Sea ice extent has large seasonal variation, providing favourable conditions for sea-ice formation and subsequent brine rejection. A new and improved setup of the regional coupled ice–ocean model Hamburg Shelf Ocean Model (HAMSOM) is applied to the Barents Sea for the period 1948–2007. Results show formation of dense water from cooling of inflowing Atlantic water to the freezing point and effective salt rejection from sea-ice growth. Bottom water temperature and salinity show significant interannual to decadal variability. The variability in dense water volume is investigated with respect to the initial autumn surface salinity, the length of the freezing season, total sea-ice growth (salt rejection) and atmospheric cooling. These factors all contribute to dense water formation, but initial salinity and total ice growth are the most important factors. Our study also illustrates the difference in dense water formation between coastal polynyas and the shallow banks. The coastal polynyas are more affected by local processes, while the shallow banks are linked to regional advection.