def METHOD_NAME(gflux=None, rflux=None, zflux=None):
    """Convert fluxes in the northern (BASS/MzLS) to the southern (DECaLS) system.
    Parameters
    ----------
    gflux, rflux, zflux : :class:`array_like` or `float`
        The flux in nano-maggies of g, r, z bands.
    Returns
    -------
    The equivalent fluxes shifted to the southern system.
    Notes
    -----
    - see also https://desi.lbl.gov/DocDB/cgi-bin/private/RetrieveFile?docid=3390;filename=Raichoor_DESI_05Dec2017.pdf;version=1
    """
    # ADM only use the g-band color shift when r and g are non-zero
    gshift = gflux * 10**(-0.4*0.013)
    w = np.where((gflux != 0) & (rflux != 0))
    gshift[w] = (gflux[w] * 10**(-0.4*0.013) * (gflux[w]/rflux[w])**complex(-0.059)).real
    # ADM only use the r-band color shift when r and z are non-zero
    # ADM and only use the z-band color shift when r and z are non-zero
    w = np.where((rflux != 0) & (zflux != 0))
    rshift = rflux * 10**(-0.4*0.007)
    zshift = zflux * 10**(+0.4*0.022)
    rshift[w] = (rflux[w] * 10**(-0.4*0.007) * (rflux[w]/zflux[w])**complex(-0.027)).real
    zshift[w] = (zflux[w] * 10**(+0.4*0.022) * (rflux[w]/zflux[w])**complex(+0.019)).real
    return gshift, rshift, zshift