Remote sensing of cirrus cloud parameters using advanced very-high-resolution radiometer 3.7- and 1 O.9-microm channels.
Remote sensing of cirrus cloud parameters using advanced very-high-resolution radiometer 3.7- and 1 O.9-microm channels.
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DOI：
10.1364/ao.32.002171
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发表时间：
1993-04
期刊：
影响因子：
1.9
通讯作者：
S. Ou;K. Liou;W. Gooch;Y. Takano
中科院分区：
文献类型：
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作者：
S. Ou;K. Liou;W. Gooch;Y. Takano
我们开发了一种检索方案，使用先进的超高分辨率辐射计 (AVHRR) 3.7 微米和 10.9 微米数据同时计算卷云的温度、光学深度和平均有效冰晶尺寸。该方法涉及从辐射传输理论导出的一组非线性代数方程的数值解。该解决方案需要根据有效消光比关联两个通道的发射率。通过使用加倍辐射传输程序来检查该比率对冰晶尺寸分布的依赖性。对卷云参数对上升流辐射亮度影响的研究表明，对于较冷的卷云和较小的冰晶尺寸，两个通道之间的亮度温度差异变得更大。我们将当前的检索方案应用于 1986 年 10 月 28 日 0930 UTC（世界标准时间 0930）在第一个国际卫星云气候学项目区域实验卷云密集实地观测区域收集的卫星数据。我们选择威斯康星州麦科伊堡附近区域（约北纬 44 度，西行 92 度）的数据进行分析。检索到的卷云高度与目标区域卫星立交桥 2 小时后在麦科伊堡进行的激光雷达测量结果相当吻合。检索到的平均有效晶体尺寸接近于卫星立交桥六小时后威斯康星州麦迪逊市上空飞机现场测量得出的尺寸。
We develop a retrieval scheme by using advanced very-high-resolution radiometer (AVHRR) 3.7- and 10.9-microm data to compute simultaneously the temperature, optical depth, and mean effective ice-crystal size for cirrus clouds. The methodology involves the numerical solution of a set of nonlinear algebraic equations derived from the theory of radiative transfer. The solution requires the correlation of emissivities of two channels in terms of the effective extinction ratio. The dependence of this ratio on ice-crystal size distribution is examined by using an adding-doubling radiative transfer program. Investigation of the effects of cirrus parameters on upwelling radiances reveals that the brightnesstemperature difference between the two channels becomes larger for colder cirrus and smaller ice-crystal sizes. We apply the current retrieval scheme to satellite data collected at 0930 UTC, 28 October 1986, over the region of the First International Satellite Cloud Climatology Project Regional Experiment CirrusIntesive Field Observation. We select the data over an area (~ 44 degrees N, 92 degrees W) near Fort McCoy, Wisconsin, for analysis. The retrieved cirrus heights compare reasonably well with lidar measurements taken at Fort McCoy 2 h after a satellite overpass at the target region. The retrieved mean effective crystal size is close to that derived from in situ aircraft measurements over Madison, Wisconsin, six hours after a satellite overpass.