介绍了libRadtran辐射传输模式中对水云和冰云辐射特征(单次散射反照率、体消光系数和不对称因子)的参数 化方案,利用该模式对水云和冰云在0.65 m、1.64 m和2.13 m的反射率进行了模拟计算,并将计算结果与SBDART的模拟结果进行了比较。结果表明,在相同条件下,水 云的libRadtran的参数化计算结果要比SBDART米散射的计算结果要小,二者在可见光区域符合的较好,在近红外区 域相差较大；不同形状冰晶的参数化模拟计算结果要比SBDART球形米散射的计算结果更为详细和准确,libRadtran在考虑 冰晶形状时的辐射传输计算要比SBDART有优势。在云微物理参数反演需要预先计算的冰云辐射查找表可 以用libRadtran代替目前广泛使用的SBDART辐射传输模式。

Parameterization of water cloud and ice cloud optical properties included in the libRadtran software package are introduced. These optical properties include single-scattering albedo, extinction coefficient and asymmetry factor. Then simulations for water cloud and ice cloud at 0.65 m, 1.64 m and 2.13 m are conducted. Comparison with SBDART simulation shows that there are similar results in the visible region and significant differences in the solar near-infrared region. Parameterization of ice cloud for various particle habits in the libRadtran have better approximation than Mie calculation for sphere ice particles used in the SBDART. A pre-computed look-up table of the bidirectional reflection in retrieving ice clouds optical thickness and effective particle radius can be improved by libRadtran.