Reply on RC2

Abstract

Ice shelves in the Amundsen Sea are thinning rapidly as ocean currents bring warm water into the cavities beneath the floating ice. While the reported melt rates for the Getz ice shelf are comparatively low for the region, its size makes it one of the largest freshwater sources around Antarctica, with potential consequences for e.g. bottom water formation downstream. Here, we use two year long mooring records (2016–2018) and 16 year long regional model simulations to describe, for the first time, the hydrography and circulation in the vicinity of the ice front between Siple and Carney Island. We find that, throughout the mooring record, temperatures in the trough remain below 0.15 °C, more than 1 °C lower than in the neighboring Siple and Dotson Trough, and we observe a mean current (0.03 m s-1) directed towards the ice front. The variability in the heat transport towards the ice front appears to be governed by wind stress over the Amundsen Sea Polynya region, potentially through interactions with the coastal current, although this hypothesis could not be confirmed by the numerical model. The model simulations suggest that the heat content in the trough during the observed period was lower than normal, due to anomalously low summertime sea ice concentration and weak winds.