Abstract

The Antarctic shelf seas are of great climatic importance due to their vigorous interactions with the atmosphere and cryosphere, which influence continental deglaciation, global sea level, and the production of dense bottom waters. However, understanding of these interactions and their impacts is confounded by sea ice, which covers the region for much of the year. In particular, little is known about the local oceanic response to the recent changes in Antarctic freshwater discharge. Here, we use satellite measurements of sea surface height (SSH) during ice-free months and an ocean circulation model to show that over the last two decades (1992-2011) Antarctic coastal sea level has risen at least 2 ± 0.8 mm/yr above the regional mean south of 50°S, and that this signal is a steric adjustment to increased glacial melt from Antarctica. Our findings demonstrate the strength of the sea level response to accelerating Antarctic discharge, and expose a significant climatic perturbation to the cryospheric forcing of the Southern Ocean.