def saturation_vapor_density(svp,
                             avg_daily_air_temp):
    """

    Parameters
    ----------
    svp : float
        saturation vapor pressure, in kilopascals
    avg_daily_air_temp : float
        Average daily air temperature, in Celsius

    Returns
    -------
    svd : float
        is the saturation vapor density, in grams per
        cubic meter
    """
    avg_daily_air_temp_kelvin = avg_daily_air_temp + 273.15
    return 2166.74 * (svp/
                      avg_daily_air_temp_kelvin)