摘要
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0.65μm、1.64μm和2.13μm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 μm, 1.64 μm and 2.13 μm 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.
出处
《大气与环境光学学报》
CAS
2010年第1期19-25,共7页
Journal of Atmospheric and Environmental Optics
