An improved semi-empirical model for the densification of Antarctic firn
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. First, the
steady-state model version is used to simulate the strong spatial variability in firn layer thickness across the Antarctic ice
sheet. Second, the time-dependent model is run for 3 Antarctic locations with different climate conditions. Surface height changes are caused by a combination of accumulation, melting
and firn densification processes. On all 3 locations, an upward trend of the surface during autumn, winter and spring is present, 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.
Authors: Ligtenberg, S.R.M., Heilsen, M.M., van de Broeke, M.R.