MPAS-Albany Land Ice (MALI): a variable-resolution ice sheet model for Earth system modeling using Voronoi grids

Abstract

Abstract. We introduce MPAS-Albany Land Ice (MALI) v6.0, a new variable-resolution land ice model that uses unstructured Voronoi grids on a plane or sphere. MALI is built using the Model for Prediction Across Scales (MPAS) framework for developing variable-resolution Earth system model components and the Albany multi-physics code base for the solution of coupled systems of partial differential equations, which itself makes use of Trilinos solver libraries. MALI includes a three-dimensional first-order momentum balance solver (Blatter–Pattyn) by linking to the Albany-LI ice sheet velocity solver and an explicit shallow ice velocity solver. The evolution of ice geometry and tracers is handled through an explicit first-order horizontal advection scheme with vertical remapping. The evolution of ice temperature is treated using operator splitting of vertical diffusion and horizontal advection and can be configured to use either a temperature or enthalpy formulation. MALI includes a mass-conserving subglacial hydrology model that supports distributed and/or channelized drainage and can optionally be coupled to ice dynamics. Options for calving include “eigencalving”, which assumes that the calving rate is proportional to extensional strain rates. MALI is evaluated against commonly used exact solutions and community benchmark experiments and shows the expected accuracy. Results for the MISMIP3d benchmark experiments with MALI's Blatter–Pattyn solver fall between published results from Stokes and L1L2 models as expected. We use the model to simulate a semi-realistic Antarctic ice sheet problem following the initMIP protocol and using 2 km resolution in marine ice sheet regions. MALI is the glacier component of the Energy Exascale Earth System Model (E3SM) version 1, and we describe current and planned coupling to other E3SM components.

Description and validation of the ice-sheet model Yelmo (version 1.0)

“…The statistics for these experiments are listed in Table 1 as well. Figure 3 shows the basal homologous temperature distribution for experiments A and F. Yelmo produces symmetrical temperature patterns in both experiments, which are consistent with both the benchmark results (Payne et al, 2000) and other more recent models (e.g., Bueler et al, 2007;Hoffman et al, 2018).…”

Description and evaluation of the Community Ice Sheet Model (CISM) v2.1

“…Code availability. Source code for CISM v2.1 can be obtained by downloading a released version from https://cism.github.io/ download.html (Hoffman et al, 2019) or by cloning the code from the public git repository at https://github.com/CISM/cism (last access: 20 January 2019). The CISM2.1 documentation, which includes detailed instructions for downloading and building the code, can be found at https://cism.github.io/documentation.html (last access: 20 January 2019).…”

initMIP-Antarctica: an ice sheet model initialization experiment of ISMIP6

“…depth-integrated higher-order) approximations (Hindmarsh, 2004), and two use a 3-D higher-order approximation (Pattyn, 2003). The other models use a combination of the Shallow Ice Approximation (SIA; Hutter, 1983) and SSA, either combining SIA for the grounded ice with SSA for the floating ice or using SSA as a sliding law and SIA for the internal deformation (Bueler and Brown, 2009). The grid resolution ranges from 4 to 32 km for models based on fixed regular grids, while models using adaptive grid refinement are able to use resolutions as low as 0.5 km in grounding zones.…”