import math


def solar_rad_campbell_to_metric(rad):
    """
    Parameters
    ------------------------------
    rad: (``float``)
        Solar radiation in MJ/hm2
    Returns
    ------------------------------
    metric_rad: (``float``)
        Solar radiation in W/m2
    """
    metric_rad = rad * (math.pow(10, 6) / 3600)
    return metric_rad