Journal Article

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

Gwyther, David E., O’Kane, Terence J., Galton-Fenzi, Benjamin K., Monselesan, Didier P., Greenbaum, Jamin S.

2018

Overview

Over the period 2003–2008, 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 1–5 year timescale (and up to 21% in the 5–10 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. Low frequency intrinsic ocean variability has an unknown impact on Antarctic ice shelves, yet can arise even in the absence of varying climate forcing. Here, the authors show that this variability significantly affects modelled basal melting under the Totten Ice Shelf, with implications for the attribution of change.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 704/106/125 / 704/829/2737 / Annual variations / Boundary conditions / Climate change / Computer simulation / Glaciers / Humanities and Social Sciences / Ice sheets / Ice shelves / Land ice / Mathematical models / Melting / multidisciplinary / Ocean models / Science / Science (multidisciplinary) / Simulation / Time / Trends / Variability