Observed interannual changes beneath Filchner-Ronne Ice Shelf linked to large-scale atmospheric circulation

• Published in: Nature Communications
• Main Authors: Hattermann, T., Nicholls, K.W., Hellmer, H., Davis, P.E.D., Janout, M.A., Østerhus, S., Schlosser, E., Rohardt, G., Kanzow, T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Research 2021
• Subjects: Antarctic; The Antarctic; Amundsen Sea; Ronne Ice Shelf; Achilles Heel; Antarc*; Filchner Ronne Ice Shelf; Filchner-Ronne Ice Shelf; Ice Sheet; Ice Shelf; Ice Shelves; Sea ice
• Online Access: http://nora.nerc.ac.uk/id/eprint/530381/; https://nora.nerc.ac.uk/id/eprint/530381/1/s41467-021-23131-x.pdf; https://www.nature.com/articles/s41467-021-23131-x

Floating ice shelves are the Achilles’ heel of the Antarctic Ice Sheet. They limit Antarctica’s contribution to global sea level rise, yet they can be rapidly melted from beneath by a warming ocean. At Filchner-Ronne Ice Shelf, a decline in sea ice formation may increase basal melt rates and accelerate marine ice sheet mass loss within this century. However, the understanding of this tipping-point behavior largely relies on numerical models. Our new multi-annual observations from five hot-water drilled boreholes through Filchner-Ronne Ice Shelf show that since 2015 there has been an intensification of the density-driven ice shelf cavity-wide circulation in response to reinforced wind-driven sea ice formation in the Ronne polynya. Enhanced southerly winds over Ronne Ice Shelf coincide with westward displacements of the Amundsen Sea Low position, connecting the cavity circulation with changes in large-scale atmospheric circulation patterns as a new aspect of the atmosphere-ocean-ice shelf system.