ismip7_run

The landice/ismip7_run test group sets up one or more experiments from the ISMIP7 protocol for both the Antarctic Ice Sheet (AIS) and the Greenland Ice Sheet (GrIS).

This functionality assumes the forcing files have already been generated using the ismip7_forcing test group and organized into the expected directory layout. It creates a consistent set of run directories for the requested experiments. Each experiment directory is self-contained with namelists, streams, forcing symlinks, and a job script ready for submission.

The test group includes two test cases:

ismip7_ais — Antarctic Ice Sheet experiments
ismip7_gris — Greenland Ice Sheet experiments

Note

This test group is not meant for automated running of experiments. Expert knowledge is recommended for conducting the actual simulations. Each experiment (step) should be submitted manually via its job script.

Experiment Matrix

The ISMIP7 core protocol defines 11 experiments per ice sheet:

Experiment	Scenario	Start	End	ESM
`historical_CESM2-WACCM`	Historical	≥1850	2014	CESM2-WACCM
`historical_MRI-ESM2-0`	Historical	≥1850	2014	MRI-ESM2-0
`ssp370_CESM2-WACCM`	SSP370	2015	2100	CESM2-WACCM
`ssp370_MRI-ESM2-0`	SSP370	2015	2100	MRI-ESM2-0
`ssp126_CESM2-WACCM`	SSP126	2015	2300	CESM2-WACCM
`ssp126_MRI-ESM2-0`	SSP126	2015	2300	MRI-ESM2-0
`ssp585_CESM2-WACCM`	SSP585	2015	2300	CESM2-WACCM
`ssp585_MRI-ESM2-0`	SSP585	2015	2300	MRI-ESM2-0
`ctrl_CESM2-WACCM`	CTRL2015	2015	2300	CESM2-WACCM
`ctrl_MRI-ESM2-0`	CTRL2015	2015	2300	MRI-ESM2-0
`ocx`	OCX	1990	2025	(reanalysis)

Unlike ISMIP6, ISMIP7 requires a separate historical simulation per ESM. Projection experiments automatically symlink their restart file from the corresponding ESM’s historical run (e.g., ssp585_CESM2-WACCM → ../historical_CESM2-WACCM/rst.2015-01-01.nc).

Usage

Process forcing data using ismip7_forcing.

Organize output into the expected directory layout:

{forcing_basepath}/
├── CESM2-WACCM_historical/
│   ├── atmosphere/
│   │   └── {mesh}_smb_CESM2-WACCM_historical_*.nc
│   └── ocean_thermal_forcing/
│       └── {mesh}_thermal_forcing_CESM2-WACCM_historical_*.nc
├── CESM2-WACCM_ssp585/
│   ├── atmosphere/
│   └── ocean_thermal_forcing/
└── ...

Create a user config file overriding the NotAvailable paths.

Set up and run:

compass setup landice/ismip7_run/ismip7_ais -f my_ismip7_ais.cfg
# Then submit job scripts from individual experiment directories

config options

All config options should be reviewed and altered as needed.

AIS config ([ismip7_run_ais]):

[ismip7_run_ais]

# Experiment list: "all", "historical", "projections", "ctrl",
# or comma-delimited experiment names
exp_list = all

# Number of MPI tasks
ntasks = 128
pio_stride = 128

# Base path to pre-processed forcing
forcing_basepath = NotAvailable

 # Initial condition and parameter files
 init_cond_path = NotAvailable
 melt_params_path = NotAvailable
 reference_surface_path = NotAvailable
 region_mask_path = NotAvailable

# Climatology files for CTRL2015 experiments
ctrl_tf_climatology_path = NotAvailable
ctrl_atm_climatology_path = NotAvailable

# OCX forcing path
ocx_forcing_path = NotAvailable

# Calving: restore or von_mises
calving_method = restore
von_mises_parameter_path = NotAvailable

# Face melting
use_face_melting = false

# Sea-level model coupling
sea_level_model = false
slm_input_ice = NotAvailable
slm_input_earth = NotAvailable
slm_earth_structure = prem_512.l60K2C.sum18p6.dum19p2.tz19p4.lm22
slm_input_others = NotAvailable
nglv = 2048

GrIS config ([ismip7_run_gris]) is similar (including reference_surface_path) but without sea-level model options

Forcing Streams

ISMIP7 uses more forcing fields than ISMIP6, at mixed temporal resolutions:

Monthly forcing (input_interval = 0000-01-00_00:00:00):

sfcMassBal — surface mass balance
surfaceAirTemperature — surface air temperature
ismip6Runoff — ice sheet runoff
ismip6_2dThermalForcing (GrIS) — ocean thermal forcing

Annual forcing (input_interval = 0001-00-00_00:00:00):

sfcMassBalLapseRate — SMB elevation lapse rate
surfaceAirTemperatureLapseRate — temperature lapse rate
ismip6shelfMelt_3dThermalForcing (AIS)

Static (input_interval = initial_only):

ismip6shelfMelt_zOcean — ocean depth coordinates (AIS only)
ismip6shelfMelt_deltaT, ismip6shelfMelt_basin, ismip6shelfMelt_gamma0 — melt parameterization coefficients

For CTRL2015 experiments, all forcing intervals are set to initial_only (constant climate).

ismip7_ais

landice/ismip7_run/ismip7_ais sets up AIS experiments with 3D ocean thermal forcing (30 vertical layers) and optional sea-level model coupling.

ismip7_gris

landice/ismip7_run/ismip7_gris sets up GrIS experiments with 2D (depth-averaged) ocean thermal forcing. Sea-level model coupling is not currently supported for GrIS. Crevasse-depth calving is the default.