Is there a package that provides an xarray-based implementation of cdutil.vertical.reconstructPressureFromHybrid?

[tomvothecoder]

Hi @xCDAT/core-developers or anybody in the xCDAT community. Have any of you come across a package that implements an xarray-based function similar to cdutil.vertical.reconstructPressureFromHybrid? I am working on refactoring e3sm_diags and e3sm_to_cmip to use xarray/xCDAT and there are references to this function that I need to replace. Thanks!

Docstring:

def reconstructPressureFromHybrid(ps, A, B, Po):
    """
    Reconstruct the Pressure field on sigma levels, from the surface pressure
    :param Ps: Surface pressure
    :param A: Hybrid Conversion Coefficient, such as: p=B.ps+A.Po.
    :param B: Hybrid Conversion Coefficient, such as: p=B.ps+A.Po.
    :param Po: Hybrid Conversion Coefficient, such as: p=B.ps+A.Po
    :param Ps: surface pressure
    .. note::
        A and B are 1d sigma levels.
        Po and Ps must have same units.
    :returns: Pressure field, such as P=B*Ps+A*Po.
    :Example:
        .. doctest:: vertical_reconstructPressureFromHybrid
            >>> P=reconstructPressureFromHybrid(ps,A,B,Po)
    """
	...

Examples Usages:

• https://github.com/E3SM-Project/e3sm_diags/blob/4a82b0ec3b2a81233b294fa505c6aa8228ecbd27/e3sm_diags/driver/utils/general.py#L132-L146
• https://github.com/E3SM-Project/e3sm_to_cmip/blob/70f7dad381ef304b022826b540df0e7b46ba9912/e3sm_to_cmip/cmor_handlers/vars/pfull.py#L38-L47
• https://github.com/E3SM-Project/e3sm_to_cmip/blob/70f7dad381ef304b022826b540df0e7b46ba9912/e3sm_to_cmip/cmor_handlers/vars/phalf.py#L39-L50

[chengzhuzhang]

Hi Tom,
We had an example in the vertical interpolation PR: Line 14 and forward in https://github.com/xCDAT/xcdat/blob/9e2800ccb77f6f118f74429ab40052019206e5d6/docs/examples/regridding-vertical.ipynb

We can wrap it in a function to construct pressure based on hybrid parameters, here is an example how geocat codes it https://github.com/NCAR/geocat-comp/blob/0263d2d77ab22a6be4d1d3f16d5bfcfc68057364/src/geocat/comp/interp_hybrid_to_pressure.py#L77

[tomvothecoder]

Thanks Jill!

[jasonb5]

cf-xarray doesn't currently support reconstructing pressure from hybrid but it provides a framework for this via decode_vertical_coords method: https://cf-xarray.readthedocs.io/en/latest/parametricz.html.

Might be an opportunity to make a PR and fill out support for decoding other parametric vertical coordinates.