thwaites¶

The landice/thwaites test group runs tests with a coarse (4-14-km) Thwaites Glacier mesh. The purpose of this test group is to provide a realistic glacier that includess an ice shelf. The mesh and initial condition are already generated. In the future, additional test cases may be added for generating a new version of the Thwaites mesh at different resolutions and using different data sources.

The test group includes three test cases, two of which have one or more steps that are variants on run_model (given other names in the decomposition and restart test cases to distinguish multiple model runs), which performs time integration of the model. There is a not an explicit smoke test, but the full_run step of the restart_test can be used as a smoke test.

The decomposition_test and restart_test test cases in this test group can only be run with the FO velocity solvers. Running with the FO solver requires a build of MALI that includes Albany. There is no integration step for the test case mesh_gen.

config options¶

The mesh_gen test case uses the default config options below. The other test cases do not use config options.

[mesh]

# number of levels in the mesh
levels = 10

# distance from ice margin to cull (km).
# Set to a value <= 0 if you do not want
# to cull based on distance from margin.
cull_distance = 10.0

# mesh density parameters
# minimum cell spacing (meters)
min_spac = 1.e3
# maximum cell spacing (meters)
max_spac = 8.e3
# log10 of max speed for cell spacing
high_log_speed = 2.5
# log10 of min speed for cell spacing
low_log_speed = 0.75
# distance at which cell spacing = max_spac
high_dist = 1.e5
# distance within which cell spacing = min_spac
low_dist = 5.e4

# mesh density functions
use_speed = True
use_dist_to_grounding_line = True
use_dist_to_edge = True

decomposition_test¶

landice/thwaites/decomposition_test runs short (2-day) integrations of the model forward in time on 16 (16proc_run step) and then on 32 cores (32proc_run step) to make sure the resulting prognostic variables are bit-for-bit identical between the two runs.

restart_test¶

landice/thwaites/restart_test first runs a short (5-day) integration of the model forward in time (full_run step). Then, a second step (restart_run) performs two subsequent 2 and 3 day integrations, where the second begins from a restart file saved by the first. Prognostic variables are compared between the “full” and “restart” runs to make sure they are bit-for-bit identical.

mesh_gen¶

landice/thwaites/mesh_gen creates a variable resolution mesh based on the the config options listed above. This will not be the same as the pre-generated 4-14km mesh used in decomposition_test and restart_test because it uses a newer version of Jigsaw. Note that the basal friction optimization is performed separately and is not part of this test case.