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The Cryosphere Discuss., 5, 1921-1948, 2011
www.the-cryosphere-discuss.net/5/1921/2011/ doi:10.5194/tcd-5-1921-2011 © Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 License. |
An improved semi-empirical model for the densification of Antarctic firn
Institute for Marine and Atmospheric research Utrecht (IMAU) P.O. Box 80000, 3508 TA Utrecht, The Netherlands
Abstract. A firn densification model is presented that simulates steady-state Antarctic firn density profiles, as well as the temporal evolution of firn density and surface height. The model uses an improved firn densification expression that is tuned to fit depth-density observations. Liquid water processes (meltwater percolation, retention and refreezing) are also included. Two applications are presented. The steady-state model version is used to simulate the strong spatial variability in firn layer thickness across the Antarctic ice sheet. The time-dependent model is run for 3 Antarctic locations. It reveals a gentle upward motion of the surface during autumn, winter and spring, while during summer there is a more rapid lowering of the surface. Accumulation and (if present) melt introduce large inter-annual variability in surface height trends, possibly hiding ice dynamical thickening and thinning.
Citation: Ligtenberg, S. R. M., Helsen, M. M., and van den Broeke, M. R.: An improved semi-empirical model for the densification of Antarctic firn, The Cryosphere Discuss., 5, 1921-1948, doi:10.5194/tcd-5-1921-2011, 2011.