Hydrological and current velocity data from moorings P1, P2, P4, P5 and P6 in the Filchner Trough region in the southern Weddell Sea, February 2017 to March 2021

Deep water formed around the Antarctic continent drives the world ocean circulation. More than 50% of this deep water is formed within only about 10% of the Antarctic circumpolar band: the Weddell Sea. Subtle changes in the circulation of the Weddell Sea can lead to major changes in floating ice shelves, with critical implications for global sea-level, the production of deep water, and the global ocean overturning circulation. The Filchner Trough on the continental shelf in the southern Weddell Sea plays an important role for the water mass exchange between the cold water on the continental shelf and the warm water off the continental shelf: It serves as a conduit for relatively warm water to flow southward across the continental shelf toward the Filchner Ronne Ice shelf and for the dense, cold water produced underneath the ice shelf to flow northward off the continental shelf to feed Antarctic Bottom Water. Four moorings (P1, P2, P4, P5) were places within the inflow pathway of the warm water at the northern entrance to the Filchner Trough on the continental shelf, and one mooring (P6) was placed off the continental shelf over the deep ocean. The mooring time series cover the period from February 2017 to March 2021 and are used to investigate the processes controlling the on-shore transport of relatively warm water onto the shelf toward the ice shelf and the interaction of the warm water with the cold dense water. The moorings provide observations of the circulation on the continental shelf and the temperature variability on small (tidal) to large (seasonal, interannual) time scales.