Numerical simulations of glacier evolution performed using
flow-line models of varying complexity
Antonija Rimac1,2, Sharon van Geffen1,2, and Johannes Oerlemans11Institute for Marine and Atmospheric Research, Utrecht University, The Netherlands 2Netherlands Earth System Science Centre, Utrecht University, The Netherlands
Received: 13 Mar 2017 – Accepted for review: 15 Mar 2017 – Discussion started: 15 Mar 2017
Abstract. The performance of two numerical models of different complexity, i.e., a Shallow Ice Approximation (SIA) and a Full-Stokes Model (FSM), is studied by analyzing glacier evolutions at various bed geometries and by applying different climatic forcings. Glacier bed geometry changes from a constant slope and a uniform width to a superimposed Gaussian bump or ice-fall on a constant slope and an exponentially varying width. Constant slopes of 0.1, 0.2 and 0.3 are chosen to study the evolution of a large, medium and small glacier, respectively. A specific mass balance serves as a climatic forcing. The steady state is reached 60, 30 and 10 years, respectively faster for large, medium and small glacier, when simulations are performed using SIA instead of FSM. Glaciers time response is studied by using step and periodic changes, and by imposing natural variability in the equilibrium-line altitude. Glacier length response time is up to 14 years longer when FSM is used compared to SIA. When periodic and natural variability are enforced, glaciers simulated using SIA lag in phase compared to the forcing up to 81.2° for glacier length and up to 56.5° for volume. Contrary to that, glaciers simulated with FSM show greater lag in phase compared to the forcing for glacier length and smaller lag for volume. The models differ in their treatment of glacier flow mechanics and differences in physical variables become apparent with increasing glacier bed slope and bed profile complexity.
Rimac, A., van Geffen, S., and Oerlemans, J.: Numerical simulations of glacier evolution performed using
flow-line models of varying complexity, Geosci. Model Dev. Discuss., doi:10.5194/gmd-2017-67, in review, 2017.
Antonija Rimac et al.
Antonija Rimac et al.
Model code and software
Capabilities and performance of Elmer/Ice, a new-generation ice sheet model
O. Gagliardini, T. Zwinger, F. Gillet-Chaulet, G. Durand, L. Favier, B. de Fleurian, R. Greve, M. Malinen, C. Martín, P. Råback, J. Ruokolainen, M. Sacchettini, M. Schäfer, H. Seddik, and J. Thies