polaris.tasks.ocean.realistic_global.init.pstar_init.RealisticPStarInitStep.init_tracers

RealisticPStarInitStep.init_tracers(ds: Dataset) → tuple[DataArray, DataArray]

Interpolate conservative temperature and absolute salinity from the pre-remapped WOA23 depth levels to the current p-star midpoints.

The WOA23 depth coordinate is positive-downward (meters); p-star midpoints are negative (geometric-height convention). This method treats p-star pseudo-heights as approximate geometric heights, which is sufficient for convergence of the outer fixed-point loop.

Parameters:

ds (xarray.Dataset) – Current p-star dataset including ZTildeMid, minLevelCell, and maxLevelCell.

Returns:

• conservative_temperature (xarray.DataArray) – CT with dimensions (Time, nCells, nVertLevels).

• absolute_salinity (xarray.DataArray) – SA with dimensions (Time, nCells, nVertLevels).