Topography Tasks

The e3sm/init/topo tasks create shared topography products and derived MPAS inputs that are reused by mesh-generation and E3SM initial-condition workflows.

Supported cubed-sphere products are:

  • ne3000

  • ne120

Supported latitude-longitude products are:

  • 1.00000_degree

  • 0.25000_degree

  • 0.12500_degree

  • 0.06250_degree

  • 0.03125_degree

Latitude-longitude product names follow the naming convention used by format_lat_lon_resolution_name(), which formats the resolution with 5 decimal places and appends _degree. For example, 0.125 becomes 0.12500_degree and 0.03125 becomes 0.03125_degree.

Standalone tasks are available to create each combined topography product:

  • e3sm/init/topo/combine_bedmap3_gebco2023/cubed_sphere/ne3000/task

  • e3sm/init/topo/combine_bedmap3_gebco2023/cubed_sphere/ne120/task

  • e3sm/init/topo/combine_bedmap3_gebco2023/lat_lon/1.00000_degree/task

  • e3sm/init/topo/combine_bedmap3_gebco2023/lat_lon/0.25000_degree/task

  • e3sm/init/topo/combine_bedmap3_gebco2023/lat_lon/0.12500_degree/task

  • e3sm/init/topo/combine_bedmap3_gebco2023/lat_lon/0.06250_degree/task

  • e3sm/init/topo/combine_bedmap3_gebco2023/lat_lon/0.03125_degree/task

The remap and cull tasks reuse these shared products when generating inputs for MPAS base meshes.

Configuration Options

These tasks create shared config files in their work directories:

  • combine_topo.cfg for combine tasks

  • remap_topo.cfg for remap tasks

  • cull_topo.cfg for cull tasks

Combine Tasks

Combine tasks use the [combine_topo] section.

The following options are set automatically from the task path and normally should not be changed by hand:

  • target_grid

  • resolution_latlon

  • resolution_cubedsphere

Common user-tunable options are:

  • method: Remapping method used when combining datasets.

  • renorm_thresh: Threshold below which interpolated fields are not renormalized.

  • ntasks and min_tasks: Target and minimum MPI task counts for remapping.

  • latmin and latmax: Latitude range over which Antarctic and global topography are blended.

  • lat_tiles and lon_tiles: Tile counts used to decompose global remapping.

Visualization tasks also use viz_combine_topo_* sections for colormap and normalization settings.

Remap Tasks

Remap tasks use the [mask_topography] and [remap_topography] sections.

Common user-tunable options are:

  • ocean_includes_grounded_ice: Whether grounded Antarctic ice is treated as part of the ocean mask.

  • description: Metadata description written to the remapped product.

  • ntasks and min_tasks: Target and minimum MPI task counts for remapping.

  • renorm_threshold: Minimum land or ocean area fraction required before renormalizing elevation variables.

  • expand_distance and expand_factor: Smoothing controls for remapped topography.

For lower-resolution cubed-sphere source topography, Polaris automatically applies lower ntasks and min_tasks defaults from remap_low_res.cfg.

Visualization steps also use viz_remapped_topo_* sections for plot styling.

Cull Tasks

Cull tasks use the [cull_mesh] section.

Common user-tunable options are:

  • cpus_per_task and min_cpus_per_task: Thread-count settings for culling.

  • include_critical_transects: Whether critical land and ocean transects from geometric_features are enforced during masking.

  • sea_ice_latitude_threshold: Latitude poleward of which ocean transects are widened to avoid land-locked sea-ice cells.

  • land_locked_cell_iterations: Number of passes used to detect and remove land-locked ocean cells.

  • land_ice_max_latitude: Southern latitude threshold used to classify critical land transects as land ice.

  • land_ice_min_fraction: Minimum land-ice fraction used in south-pole flood filling for the land-ice mask.