Work Package 5 – Ice sheet impacts on global ocean circulation (O5) examines the impact of ice sheet meltwater discharge on deep water formation and export from the poles, and the ultimate impact upon large scale ocean circulation, including the AMOC and ACC.

We will make the first sustained mooring observations of the primary AABW pathway from the Weddell Sea to the global ocean. This fate of this water and its contribution to the AMOC will be observed via new instrumentation of the SAMBA array in collaboration with SAMOC partners.

In WP5, we will also employ a novel inverse approach utilising oxygen isotope concentrations, resolving decadal to centennial changes in deep water properties. New model simulations will assess the impact of increased glacial melting (WP4) on global ocean circulation using a coupled Greenland Ice Sheet-climate model (NorESM-CISM) and an ocean model incorporating state-of-the-art deep ocean mixing parameterisations (NEMO). These models will investigate the relative role of northern vs southern sources of deep water and the influence of ice melt upon the AMOC on millennial timescales.

Close collaboration on AMOC variability is planned with WP6 and the successful part a) consortium of the present call.