Thin cirrus clouds - Seasonal distribution over oceans deduced from Nimbus-4 IRIS
Thin cirrus clouds - Seasonal distribution over oceans deduced from Nimbus-4 IRIS
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薄卷云 - 根据 Nimbus-4 IRIS 推导出海洋上空的季节分布
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
T. Styles
中科院分区：
文献类型：
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作者：
C. Prabhakara;R. S. Fraser;G. Dalu;Man;R. Curran;T. Styles
在飞机宽波段红外辐射计的测量中，观测到了由于光学薄云而引起的红外窗口区10.8和12.6 μm波段消光的光谱差异。由Nimbus-4号卫星上的高分辨率红外干涉仪光谱仪进行的测量也揭示了类似的光谱特性，该卫星的视场为1095公里。这些观测结果表明，12.6 μm云粒子的消光比10.8 μm云粒子的消光大得多。云中的水或冰粒子都可以解释这种消光的光谱差异，只要粒子小于辐射的波长。这种光谱效应证明与多重散射辐射传输计算的帮助下。由于IRIS资料在距高空冷云中心100 ~ 200 km处显示了这一光谱特征，推测这一特征与高空冷云的扩散有关。
Abstract Spectral differences in the extinction between the 10.8 and 12.6 μm bands of the infrared window region, due to optically thin clouds, are observed in the measurements made by a broad-band infrared aircraft radiometer. Similar spectral properties are also revealed by the measurements made by the high-resolution infrared inter-ferometer spectrometer (IRIS) aboard the Nimbus-4 satellite, which had a field of view of ∼ 95 km. These observations show that the extinction due to cloud particles at 12.6 μm is appreciably larger than that at 10.8 μm. Both water or ice particles in the clouds can account for such spectral difference in extinction provided that the particles are smaller than the wavelength of radiation. This spectral effect is demonstrated with the help of multiple scattering radiative transfer calculations. As the IRIS data reveal this spectral feature, about 100 to 200 km away from the center of high altitude cold clouds (∼ 230 K), it is inferred that this feature is related to the sprea...