Intrinsic processes drive variability in basal melting of the Totten Glacier Ice Shelf

• Published in: Nature Communications
• Main Authors: Gwyther, DE, O'Kane, TJ, Galton-Fenzi, BK, Monselesan, DP, Greenbaum, JS
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2018
• Subjects: Earth Sciences; Oceanography; Physical oceanography; Totten Glacier; Ice Shelf; Totten Ice Shelf
• Online Access: https://doi.org/10.1038/s41467-018-05618-2; http://www.ncbi.nlm.nih.gov/pubmed/30087352; http://ecite.utas.edu.au/127714

Over the period 20032008, the Totten Ice Shelf (TIS) was shown to be rapidly thinning, likely due to basal melting. However, a recent study using a longer time series found high interannual variability present in TIS surface elevation without any apparent trend. Here we show that low-frequency intrinsic ocean variability potentially accounts for a large fraction of the variability in the basal melting of TIS. Specifically, numerical ocean model simulations show that up to 44% of the modelled variability in basal melting in the 15 year timescale (and up to 21% in the 510 year timescale) is intrinsic, with a similar response to the full climate forcing. We identify the important role of intrinsic ocean variability in setting the observed interannual variation in TIS surface thickness and velocity. Our results further demonstrate the need to account for intrinsic ocean processes in the detection and attribution of change.