Potential regime shift in decreased sea ice production after the Mertz Glacier calving

• Published in: Nature Communications
• Main Authors: Tamura, T, Williams, GD, Fraser, AD, Ohshima, KI
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2012
• Subjects: Earth Sciences; Oceanography; Physical Oceanography; Antarctic; East Antarctica; Mertz Glacier; Antarc*; Antarctica; Iceberg*; Sea ice
• Online Access: https://doi.org/10.1038/ncomms1820; http://ecite.utas.edu.au/78227

Variability in dense shelf water formation can potentially impact Antarctic Bottom Water(AABW) production, a vital component of the global climate system. In East Antarctica, theGeorge V Land polynya system (142150E) is structured by the local icescape, promoting seaice formation that is driven by the offshore wind regime. Here we present the first observationsof this region after the repositioning of a large iceberg (B9B) precipitated the calving of theMertz Glacier Tongue in 2010. Using satellite data, we find that the total sea ice productionfor the region in 2010 and 2011 was 144 and 134 km 3 , respectively, representing a 1420%decrease from a value of 168 km 3 averaged from 20002009. This abrupt change to theregional icescape could result in decreased polynya activity, sea ice production, and ultimatelythe dense shelf water export and AABW production from this region for the coming decades.