polaris.ocean.vertical.ztilde.pressure_from_pseudothickness

polaris.ocean.vertical.ztilde.pressure_from_pseudothickness(surf_pressure: DataArray | float, pseudothickness: DataArray) → tuple[DataArray, DataArray]

Compute gauge pressure at layer interfaces and midpoints given surface gauge pressure and pseudo-thicknesses. Unlike pressure_from_geom_thickness(), this needs no specific volume and no iteration, since a pseudo-thickness is a pressure increment:

dp = RhoSw * g * h_tilde

Parameters:

• surf_pressure (float or xarray.DataArray) – The surface gauge pressure at the top of the water column (zero for a free surface open to the atmosphere).

• pseudothickness (xarray.DataArray) – The pseudo-thickness of each layer, set to zero for invalid layers.

Returns:

• p_interface (xarray.DataArray) – The gauge pressure at layer interfaces.

• p_mid (xarray.DataArray) – The gauge pressure at layer midpoints.