中文摘要：

利用海气耦合辐射传输模型（COART）模拟粗糙表面不同观测几何的离水辐射亮度和恰水面之下上行辐射亮度,研究了离水辐射亮度的空间分布特征、恰水面之下上行辐射亮度透射系数的空间分布特征以及粗糙表面对其空间分布特征的影响。研究结果表明,恰水面之下上行、下行辐照度随入射光太阳天顶角的增加而减小,这种衰减特征与入射光太阳天顶角的余弦值呈线性关系。离水辐射亮度的空间分布特征明显且该特征不受风生粗糙表面的影响。离水辐射亮度随观测天顶角的变化规律可用天顶角的一元三次方程拟合。水平海面恰水面之下上行辐射亮度透射系数不因观测方位角的变化而变化,随观测天顶角的增加透射系数减小,并与观测天顶角正切值的平方线性相关。粗糙表面恰水面之下上行辐射亮度透射系数随观测方位角变化较小,随观测天顶角变化较大,透射系数与观测天顶角正切值的平方之间线性关系依然存在。

英文摘要：

COART, a coupled ocean and atmosphere radiative transfer model, was used to simulate the water-leaving radiance of a rough surface and upward radiance just below the surface under varying observation geometric angles. Using these simulations, we analyzed the spatial distribution characteristics of the water-leaving radiance and the transmission co- efficient of the upward radiance just below the surface, and discussed the effects of rough surface on these distribution characteristics. The results shows that downward and upward irradiances just below the surface decrease as solar zenith angle （SZA） increases, with a line- ar relations to the cosine value of solar zenith angle. The spatial distribution characteristics of the water-leaving radiance are not involved with wind-driven rough surface. A simple cu- bic equation was developed to fit water-leaving radiance change to viewing zenith angle. Un- der the conditions of the level sea surface, the transmission coefficient of the upward radiance just below the surface does not change with the viewing azimuth angle, however, it decreases with the increasing viewing zenith angle and is linear to its square tangent value. On a rough surface, the viewing zenith angle plays a more important role in determining the transmission coefficient of the upward radiance just below the surface than viewing azimuth angle. In addi- tion, the linear relationship also exists between transmission coefficient and the square tan- gent value of viewing zenith angle.