Source code for pycif.plugins.transforms.complex.moist2dry.adjoint

def adjoint(
        transf,
        inout_datastore,
        controlvect,
        obsvect,
        mapper,
        di,
        df,
        mode,
        runsubdir,
        workdir,
        onlyinit=False,
        **kwargs
):
    """Apply the moist-to-dry conversion factor to the adjoint sensitivity.

    The adjoint of :func:`forward`: multiplies ``adj_out`` of the species
    input by the same ``dry_coef`` scalar used in the forward pass.

    Note: the sensitivity w.r.t. specific humidity ``q`` is not computed
    (``q`` is treated as a fixed diagnostic field, not a control variable).

    Args:
        transf (Plugin): moist2dry plugin instance.
        inout_datastore (dict): mutable datastore.
        controlvect: unused.
        obsvect: unused.
        mapper (dict): transform mapper.
        di (datetime): sub-simulation start date.
        df (datetime): sub-simulation end date.
        mode (str): ``'adj'``.
        runsubdir (str): unused.
        workdir (str): unused.
        onlyinit (bool): if ``True``, return immediately.
        **kwargs: unused.
    """
    ddi = min(di, df)

    if onlyinit:
        return

    # Constants
    Rdry = 287.05
    Rvapor = 461.5
    R = 8.314462
    beta = (Rvapor - Rdry) / Rvapor

    trid_out = (transf.component[0], transf.parameter[0])
    q = inout_datastore["inputs"][
        ("specific_humidity", transf.parameter[0])][ddi]["spec"]

    dry_coef = (1 - beta * q / (1 - q)) \
               * R / Rdry / transf.molmass * 1000 * 1e9

    inout_datastore["inputs"][trid_out][ddi]["adj_out"] \
            = inout_datastore["inputs"][trid_out][ddi]["adj_out"] * dry_coef