------------------------------------------------------------------------------- "Response of surface topography to basal variability along glacial flowlines" by Ng, F.S.L., Igneczi, A., Sole, A.J. and Livingstone, S.J. ------------------------------------------------------------------------------- This ORDA respository location contains all simulated data and the core MATLAB code of the above manuscript. The MATLAB code implements the nonstationary transfer in Eqns. (6), (7) and (8) of the manuscript and consists of 3 files: "nonstat_transfer.m" "TSB.m" "TSC.m". Please see the following for descriptions of the files carrying simulated data. The files are presented in both Excel format and MATLAB .mat format. 1. Synthetic Case Studies ------------------------- Datafiles of the results of 3 simulations: Run Syn1: "Run_Syn1.mat", "Run_Syn1.xlsx" Run Syn2: "Run_Syn2.mat", "Run_Syn1.xlsx" Run Syn3: "Run_Syn3.mat", "Run_Syn1.xlsx" Variables: x horizontal distance coordinate B bed elevation (unsmoothed) S surface elevation (unsmoothed) alpha mean surface slope angle (degree) C mean basal slip ratio u_s surface flow speed observed in the finite-element model of the steady-state glacier b bed topographic perturbation c bed slipperiness perturbation s surface topographic perturbation observed in the finite-element model of the steady-state glacier s_p surface topographic perturbation predicted by the nonstationary transfer method FEM_x horizontal positions x in the finite-element model of the steady-state glacier FEM_y vertical positions y in the finite-element model of the steady-state glacier FEM_u horizontal velocity components u in the finite-element model of the steady-state glacier FEM_v vertical velocity components v in the finite-element model of the steady-state glacier FEM_p pressure p in the finite-element model of the steady-state glacier 2. Real Case Study: Columbia flowline ------------------------------------- Datafile of results of the 2007 simulation: "Run_Columbia_2007.mat", "Run_Columbia_2007.xlsx" Variables: x horizontal distance coordinate (km) B_orig bed elevation, metre (unsmoothed) B bed elevation, metre (smoothed) S_orig surface elevation, metre (unsmoothed) S surface elevation, metre (smoothed) H ice thickness, metre (smoothed) alpha mean surface slope angle (degree) C mean basal slip ratio u_s observed surface flow speed (m/d) b bed topographic perturbation (m) s observed surface topographic perturbation (m) s_p predicted surface topographic perturbation (m) Datafile of results of the 2012 simulation: "Run_Columbia_2012.mat", "Run_Columbia_2012.xlsx" Variables: x horizontal distance coordinate (km) B_orig bed elevation, metre (unsmoothed) B bed elevation, metre (smoothed) S_orig surface elevation, metre (unsmoothed) S surface elevation, metre (smoothed) H ice thickness, metre (smoothed) alpha mean surface slope angle (degree) C_SPR mean basal slip ratio in spring 2011 C_AUT mean basal slip ratio in autumn 2011 u_s_SPR observed surface flow speed in spring 2011 (m/d) u_s_AUT observed surface flow speed in autumn 2011 (m/d) b bed topographic perturbation (m) s observed surface topographic perturbation (m) s_p_SPR predicted surface topographic perturbation (m) using spring 2011 flow speeds s_p_AUT predicted surface topographic perturbation (m), using autumn 2011 flow speeds s_p_no_sliding predicted surface topographic perturbation (m) in the 'no sliding' case 3. Real Case Study: Nordenskiold flowline ----------------------------------------- Datafile of simulation results in Experiments 1, 2 and 3 and an experiment assuming no basal slip ('no slip' case): "Runs_Nordenskiold.mat", "Runs_Nordenskiold.xlsx" Variables: x horizontal distance coordinate (km) B_orig bed elevation, metre (unsmoothed) B bed elevation, metre (smoothed) S_orig surface elevation, metre (unsmoothed) S surface elevation, metre (smoothed) H ice thickness, metre (smoothed) alpha mean surface slope angle (degree) MacGregor_u_s_over_u_d estimates of surface flow speed divided by deformation speed assuming temperate ice, obtained from the MacGregor et al.'s (2016) dataset C_Exp1 mean basal slip ratio in Experiment 1 C_Exp2 mean basal slip ratio in Experiment 2 C_Exp3 mean basal slip ratio in Experiment 3 beta1_Exp1 optimised value of beta1 in Experiment 1 beta2_Exp1 optimised value of beta2 in Experiment 1 beta1_Exp2 optimised value of beta1 in Experiment 2 beta2_Exp2 optimised value of beta2 in Experiment 2 beta1_Exp3 optimised value of beta1 in Experiment 3 beta2_Exp3 optimised value of beta2 in Experiment 3 b bed topographic perturbation (m) s observed surface topographic perturbation (m) s_p_Exp1 predicted surface topographic perturbation (m) in Experiment 1 s_p_Exp2 predicted surface topographic perturbation (m) in Experiment 2 s_p_Exp3 predicted surface topographic perturbation (m) in Experiment 3 s_p_NoSlip predicted surface topographic perturbation (m) when basal slip is switched off ----------------------- -----------------------