global_ocean

This category contains ocean preprocessing tasks that are upstream of any particular MPAS mesh. The first task builds a reusable World Ocean Atlas 2023 (WOA23) hydrography product on the native 0.25-degree latitude-longitude grid.

supported models

This task is model-independent and does not require either MPAS-Ocean or Omega to be built.

woa23

This task is the Polaris port of the legacy Compass utility/extrap_woa workflow. It combines January and annual WOA23 climatologies, uses a cached e3sm/init combined-topography product on the WOA grid to define the ocean mask used during preprocessing, and then fills missing temperature and salinity values through staged horizontal and vertical extrapolation.

The task can be set up with:

polaris setup -t ocean/global_ocean/hydrography/woa23 ...

description

The task is organized into three inspectable steps:

1. combine_topo from the e3sm/init component is used to combine topography GEBCO and Bedmap3 datasets on the WOA23 0.25-degree latitude-longitude grid.

2. combine creates woa_combined.nc by combining January and annual WOA23 in-situ temperature and practical-salinity fields, then deriving conservative temperature and absolute salinity.

3. extrapolate creates the final woa23_decav_0.25_jan_extrap.nc product.

This layout is intended to match Polaris shared-step conventions so the WOA23 preprocessing pipeline can later be reused by mesh-dependent global_ocean initialization tasks.

mesh

N/A. This task operates on the native WOA23 latitude-longitude grid rather than an MPAS mesh.

vertical grid

N/A. The task preserves the standard WOA23 depth levels.

initial conditions

The source fields come from the WOA23 January and annual climatologies in the Polaris input database.

forcing

N/A.

time step and run duration

N/A.

config options

# Options related to generating a reusable WOA23 hydrography product
[woa23]

# the minimum weight sum needed to mark a new cell valid in horizontal
# extrapolation
extrap_threshold = 0.01

cores

The local combine and extrapolate steps run serially. The combine_topo step is intended to use the cached e3sm/init output because regenerating the combined topography product is substantially more expensive.