def net_radiation_grass(ra_24, l_net, r0_grass=0.23):
    """
    Computes the net radiation for reference grass

    .. math ::
        Q^{*} = \\left[\\left(1-\\alpha_{0, grass}\\right)S^{\\downarrow}-L^{*}-I\\right]

    Parameters
    ----------
    ra_24 : float
        daily solar radiation
        :math:`S^{\\downarrow}`
        [Wm-2]
    l_net : float
        daily net longwave radiation
        :math:`L^{*}`
        [wm-2]
    r0_grass : float
        albedo for reference grass
        :math:`alpha_{0}_grass`
        [-]

    Returns
    -------
    rn_24_grass : float
        daily net radiation for reference grass
        :math:`Q^{*}`
        [Wm-2]

    Examples
    --------
    >>> import ETLook.radiation as rad
    >>> rad.net_radiation_grass(ra_24=123., l_net=24.)
    70.7
    """
    return (1 - r0_grass) * ra_24 - l_net
