def is_additional_coordinate_variable(var):
    """
    check if a variable belongs to a list of known constant coordinate variables

    Parameters
    ----------
    var : xarray.DataArray

    Returns
    -------
    bool :
           True = variable is not different for ensemble members
    """

    # list of excluded variables from different models
    excluded = {
        # COSMO variables
        "time_bnds": ("time", "bnds"),
        "slonu": ("rlat", "srlon"),
        "slatu": ("rlat", "srlon"),
        "slonv": ("srlat", "rlon"),
        "slatv": ("srlat", "rlon"),
        "vcoord": ("level1",),
        "soil1_bnds": ("soil1", "bnds"),
        "rotated_pole": (),
        "height_2m": (),
        "height_10m": (),
        "height_toa": (),
        "wbt_13c": (),
    }

    # variable is in excluded list?
    if var.name in excluded and excluded[var.name] == var.dims:
        return True
    else:
        return False