Inverse Model Results for WAIS

This page contains the results of a basal drag inversion performed for the West Antarctic Ice Sheet (WAIS). We provide the results in NetCDF files of our six conducted experiments in the associated (not yet published) study, showing the basal drag and basal drag coefficient, as well as the outputs of the 1D steady-state thermal model. In addition, the Matlab scripts used to generate the figures in our manuscript and the finite element mesh are uploaded. 

To perform the inversion and L-curve analysis, we rely on the inversion model presented in Wolovick et al. (2023) (available at https://doi.org/10.5281/zenodo.7798650). All parameters and the added code are included in an uploaded spreadsheet (Parameters_ISSMInversion.xlsx). 

Name conventions 

• m#: Describes the exponent in the sliding law.  The values can bet set to m1 (linear sliding) or m3 (non-linear sliding).
• Ntype:  Describes the effective pressure source in the sliding law.  Values are "noN" (i.e., Weertman sliding), "Nop" (i.e., parameterized effective pressure) and "Ncuas" (i.e., effective pressure used from subglacial hydrology CUAS-MPI).
• Budd, Weertman: Describes the two different sliding laws we use in this manuscript. Budd uses an effective pressure source and Weertman does not use an effective pressure field. 

Figure scripts

The following scripts generate all figures shown in the manuscript: 

• AllLcurveFigures_v1.m: Creates Figure 6 in the manuscript. 

• BestDragFigure_v1.m: Creates Figure 13, Figure 14 and  Figure 16 in the manuscript. 

• BestInversionComparisonFigure_v1.m: Creates Figure 15 in the manuscript. 

• ConvergenceFigure_v1.m: Creates Figure 7 in the manuscript. 

• DragCoeffComparisonFigure_N_m_v1.m: Creates Figure 11 in the manuscript. 

• DragLakeCandidatesFigure_v1.m: Creates Figure 17 and 18 in the manuscript. 

• EffectivePressureFigure_v1.m: Creates Figure 5 in the manuscript. 

• LcurveComparisonFigure_m_Ncuas_v1.m: Creates Figure 12 in the manuscript. 

• LcurveComparisonFigure_N_m_v1.m: Creates Figure 9 and Figure 10, as well as the Table 1 in the manuscript. 

• MeshFigure_v1.m: Creates Figure 3 in the manuscript. 

• ModelSetupFigure_v1.m: Creates Figure 2 in the manuscript. 

• SubdomainLcurveFigure_v1.m: Creates the subfigures of Figure 8 in the manuscript. 

• ThermalFigure_v1.m: Creates Figure 4 in the manuscript. 

Input 

• Mesh_WAIS_500m-19km.mat: mat-file of finite-element mesh for WAIS study domain. 

Inversion results 

• BestInversionResult_WAIS_m3_Ncuas_bestlambda-0.5.nc: Best basal drag and squared drag coefficient result for the experiment m=3, Ncuas evaluated at the best lambda value 0.5 determined with the L-curve analysis. 

• BestInversionResult_WAIS_m3_Ncuas_lambda-0.562.nc: Best basal drag and squared drag coefficient result for the experiment m=3, Ncuas evaluated at the lambda value 0.562 determined with the L-curve analysis. 

• InversionResult_WAIS_m1_Ncuas_lambda-1.nc: Basal drag and squared drag coefficient result for the experiment m=1, Ncuas evaluated at the lambda value 1 determined with the L-curve analysis. 

• InversionResult_WAIS_m3_Nop_lambda-0.1.nc: Basal drag and squared drag coefficient result for the experiment m=3, Nop evaluated at the lambda value 0.1 determined with the L-curve analysis. 

• InversionResult_WAIS_m1_Nop_lambda-3.16.nc: Basal drag and squared drag coefficient result for the experiment m=1, Nop evaluated at the lambda value 3.16 determined with the L-curve analysis. 

• InversionResult_WAIS_m3_noN_lambda-3.16.nc: Basal drag and squared drag coefficient result for the experiment m=3, using a Weertman sliding-law evaluated at the lambda value 3.16 determined with the L-curve analysis. 

• InversionResult_WAIS_m1_noN_lambda-0.316.nc: Basal drag and squared drag coefficient result for the experiment m=1, using a Weertman sliding-law evaluated at the lambda value 0.316 determined with the L-curve analysis. 

• ThermalOutput_WAIS.nc: Basal temperature, basal melt rates and depth-averaged rheology output from the used 1D thermal model, as well as the parameterized effective pressure Nop and the effective pressure Ncuas determined from a subglacial hydrology model.