Airborne measurements of ground and cloud spectral albedos under low aerosol loads
Airborne measurements of ground and cloud spectral albedos under low aerosol loads
复制标题
低气溶胶负荷下地面和云光谱反照率的机载测量
DOI：
10.1029/2004jd004768
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发表时间：
2004
影响因子：
--
通讯作者：
E. Jäkel
中科院分区：
文献类型：
--
作者：
A. Webb;A. Kylling;M. Wendisch;E. Jäkel
[1] 光谱反照率测量是由三个机载系统（两架飞机和一个气球）在英国东安格利亚平坦的耕地上空和云层上进行的。在不同飞行高度测量的光谱反照率包括飞机/气球下方大气的反向散射，必须将其去除以获得区域光谱表面反照率。来自机载分光辐射计的数据显示，UVB（波长范围在 280-320 nm 之间）的面积表面反照率约为 0.02，随着波长的增加而增加，在 500 nm 处约为 0.05。云反照率是在两个不同的层云上方测量的，一层是完全阴云密布的，一层是破碎的。阴云层上方的反照率与波长无关，其值在 0.62 到 0.85 之间，具体取决于云上方的位置和高度。在破碎的云层之上，平均反照率光谱显示出来自下垫面的清晰光谱反射特征与云反照率特征的混合。
[1] Spectral albedo measurements have been made by three airborne systems (two aircraft and one balloon) over the flat arable land of East Anglia, UK, and above clouds. The spectral albedos measured at the various flight altitudes include the backscattering of the atmosphere beneath the aircraft/balloon, which has to be removed to get the areal spectral surface albedo. Data derived from the airborne spectroradiometers showed the areal surface albedo to be about 0.02 in the UVB (wavelength range between 280–320 nm), increasing with wavelength to about 0.05 at 500 nm. The cloud albedos were measured above two different stratus layers, one completely overcast and one broken. Above the overcast cloud sheet the albedo was independent of wavelength with values between 0.62 and 0.85 depending on position above cloud and altitude. Above the broken cloud layer the averaged albedo spectra showed clear spectral reflection features from the underlying surface mixed with the cloud albedo signatures.