EGU24-4785, updated on 08 Mar 2024
https://doi.org/10.5194/egusphere-egu24-4785
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Large-scale climate modes dominate recent ice mass and elevation variations in much of East Antarctica

Matt King1,2, John Bright Ayabilah1,2, Poul Christoffersen2,3, Tessa Vance3,4, and Danielle Udy3
Matt King et al.
  • 1School of Geography, Planning, and Spatial Sciences, University of Tasmania, Hobart, Australia (Matt.King@utas.edu.au)
  • 2Australian Centre for Excellence in Antarctic Science, University of Tasmania, Hobart, Australia
  • 3Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
  • 4Australian Antarctic Program Partnershio, University of Tasmania, Hobart, Australia

Large-scale climate modes have recently been shown to dominate the non-linear variability of Antarctic mass over the last 20 years. We explore these results in further detail in the context of East Antarctica and expand on this work to report on new analyses of Antarctic elevation change from satellite altimetry. Altimetric measurements provide insights into spatial variation of these signals at two orders of magnitude higher spatial resolution than mass-change measurements from GRACE, allowing for resolution of variability at sub-glacier scale. Exploring the same period as the GRACE data (2002-2021) we show that about 75% of the variance of the Totten Glacier elevation can be explained by a combination of Southern Annular Mode (SAM) and ENSO. Denman Glacier shows almost no non-linear variance over 2002-2021 but about 30% of the present signal is explainable by SAM with no evident ENSO response. Despite this, much of the signal is not focused on the outlet glaciers but diffusely spread across the interior, consistent with surface mass balance. We show that much of this signal can be explained by models of firn densification, although different models have different levels of agreement with the data at relevant decadal periods. We will show detailed results for Wilkes Subglacial Basin and Dronning Maud Land.

How to cite: King, M., Ayabilah, J. B., Christoffersen, P., Vance, T., and Udy, D.: Large-scale climate modes dominate recent ice mass and elevation variations in much of East Antarctica, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4785, https://doi.org/10.5194/egusphere-egu24-4785, 2024.