Parameter sensitivity analysis of dynamic ice sheet models-Numerical computations

TL;DR

This paper investigates how small changes in friction and topography affect ice sheet models by solving adjoint equations numerically, providing insights into model sensitivity for both full Stokes and shallow shelf approximations.

Contribution

It introduces a numerical approach to quantify parameter sensitivity in ice sheet models using adjoint equations, applicable to complex and simplified scenarios.

Findings

Sensitivity varies with model type and perturbation location

Numerical results align with analytical solutions in simplified cases

Provides a framework for assessing model robustness

Abstract

The friction coefficient and the base topography of a stationary and a dynamic ice sheet are perturbed in two models for the ice: the full Stokes equations and the shallow shelf approximation. The sensitivity to the perturbations of the velocity and the height at the surface is quantified by solving the adjoint equations of the stress and the height equations providing weights for the perturbed data. The adjoint equations are solved numerically and the sensitivity is computed in several examples in two dimensions. Comparisons are made with analytical solutions to simplified problems.