Does dust change the clear sky top of atmosphere shortwave flux over high surface reflectance regions?
Does dust change the clear sky top of atmosphere shortwave flux over high surface reflectance regions?
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尘埃是否会改变高表面反射率区域上大气短波通量的晴空顶部？
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
S. Christopher
中科院分区：
文献类型：
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作者：
F. Patadia;E. Yang;S. Christopher
使用四个流辐射传输计算，卫星导出的558 nm气溶胶光学厚度和大气顶部（TOA）宽带辐射通量，我们研究了矿物尘埃气溶胶对撒哈拉沙漠上空晴空TOA短波（0.3-5 μm）通量的影响[30 E-10 W，15 N-30 N]。在非常明亮的表面（表面反射率> 35%），TOA短波通量，从卫星测量和模式计算，几乎是不敏感的尘埃光学厚度的增加。低于这个表面散射值，称为临界散射值，矿物尘埃气溶胶显示散射效应，高于这个值，它们显示吸收效应。因此，在具有大范围的表面散射值的沙漠地区，散射和吸收效应相互补偿，从而使得TOA短波气溶胶辐射效应相当小。
Using four stream radiative transfer calculations, satellite‐derived aerosol optical thickness at 558 nm and top of atmosphere (TOA) broadband radiative fluxes we examine the effect of mineral dust aerosols on the clear sky TOA shortwave (0.3–5 μm) fluxes over the Saharan desert [30E‐10W, 15N‐30N]. Over very bright surfaces (surface albedo > 35%), the TOA shortwave flux, from both satellite measurements and model calculations, is nearly insensitive to the increase in dust optical thickness. Below this surface albedo value, known as the critical albedo, mineral dust aerosols show scattering effects and above this they show absorbing effects. Therefore, over desert regions with a large range of surface albedo values, scattering and absorbing effects compensate each other thereby making the TOA shortwave aerosol radiative effect rather small.