Glacial ice and atmospheric forcing on the Mertz Glacier Polynya over the past 250 years

• Published in: Nature communications Vol. 6; no. 1; p. 6642
• Main Authors: Campagne, P., Crosta, Xavier, Houssais, M.N., Swingedouw, D., Schmidt, S., Martin, A., Devred, E., Capo, S., Marieu, V., Closset, I., Massé, G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24.03.2015; Nature Publishing Group
• Subjects: 704/106/2738; Climatology; Earth Sciences; Humanities and Social Sciences; multidisciplinary; Ocean, Atmosphere; Oceanography; Science; Science (multidisciplinary); Sciences of the Universe
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms7642

The Mertz Glacier Polynya off George V Land, East Antarctica, is a source of Adélie Land Bottom Water, which contributes up to ~25% of the Antarctic Bottom Water. This major polynya is closely linked to the presence of the Mertz Glacier Tongue that traps pack ice upstream. In 2010, the Mertz Glacier calved a massive iceberg, deeply impacting local sea ice conditions and dense shelf water formation. Here we provide the first detailed 250-year long reconstruction of local sea ice and bottom water conditions. Spectral analysis of the data sets reveals large and abrupt changes in sea surface and bottom water conditions with a ~70-year cyclicity, associated with the Mertz Glacier Tongue calving and regrowth dynamics. Geological data and atmospheric reanalysis, however, suggest that sea ice conditions in the polynya were also very sensitive to changes in surface winds in relation to the recent intensification of the Southern Annular Mode. The Mertz Glacier Polynya—a site of sea ice production and Antarctic Bottom Water formation—was strongly impacted following the calving of a massive iceberg in 2010. Here, the authors present a 250-year long sea ice reconstruction from the region and present evidence for a ~70-year calving cyclicity.