非球形气溶胶对近红外偏振辐射传输的影响及等效球形误差分析

摘要

In order to estimate the impact of non-spherical aerosol on polarized radiative transfer,the sensitivity of radiance and polarized radiance to aerosol shape was analyzed based on T Matrix method and MACAR_VSPART.In addition,the simulation errors due to the approximation that taking the non-spherical particles as sphere ones were discussed.The simulation results show that,for radiance and polarized radiance,shape sensitivities are different at different directions.The angular distributions of shape sensitivity coefficient are typical for specified solar zenith angles,which is helpful for the data selection of remote sensing process to avoid the influence of aerosol shape.Obvious simulation errors are caused by taking the non-spherical aerosol particles as sphere ones,especially for polarized radiance.The impact of shape on upwelling diffuse light at the top of atmosphere is much stronger than down-welling diffuse light at surface.%为定量评估非球形气溶胶对偏振辐射传输的影响,基于T矩阵模型及自主开发的矢量辐射传输模式MACAR_VSPART,讨论了漫射光辐亮度及偏振辐亮度对粒子形状的敏感性,分析了气溶胶球形假设造成的漫射光模拟偏差.结果表明,不同方向漫射光的辐亮度及偏振辐亮度对形状的敏感性不一致,且其形状敏感强度的空间分布呈现特定的特征,该特征可为气溶胶遥感过程中有效观测数据的选取提供依据.等效球形假设可造成较大的漫射光模拟偏差,其中偏振辐亮度尤为显著;天顶上行漫射光对粒子形状的敏感性远强于地面下行漫射光.