REMOTE SENSING OF MICROPHYSICAL AND RADIATIVE PROPERTIES OF ICE CLOUDS

冰云微观物理和辐射特性的遥感

• 批准号: 13440136
• 负责人: ASANO Shoji
• 金额: $ 9.15万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440136/
• 关键词: Ice clouds; Remote sensing; Cloud Radar; Lidar; Cloud-physical properties; Radiative properties; Scattering by nonspherical particles; spectroscopic measurements; 95GHz雲レーダ; ライダー; 非球形粒子光散乱; 分光日射計

The major purpose of the present study is to develop a synergy observational technique to retrieve microphysical and radiative properties of ice clouds by combining the ground-based active and passive remote sensing, and to validate its effectiveness for the planed satellite-borne cloud radar and lidar for measuring ice clouds from space. We have developed the transfer computation scheme of shortwave (solar) and longwave (infrared) radiation for cloudy atmospheres with ice clouds. By using the computation scheme, we have simulated the observed radiative properties for mixed-phase clouds and mid-latitude cirrostratus clouds and studied the relationship between the microphysical properties and radiative properties of the clouds containing ice particles. A sensitivity study suggested that microphysical properties of mixed-phase clouds can be retrieved by using cloud radars with dual frequencies at 35-GHz and 95-GHz. Further, we have developed a quasi-analytic solution of the three-dimensi … More onal radiative transfer equation for inhomogeneous atmospheres. The preliminary computation showed cloud in homogeneity substantially affects the radiation fields, especially, of the transmitted radiances ; this suggests that remote sensing of cloud properties from the transmitted solar radiance measurements is not-practical.We have developed a new forward algorithm for the retrieval of effective size and ice water content of ice clouds by using a 95-GHz cloud radar collocated with an optical lidar of wavelength at 0.532 μm. The algorithm enables us to estimate vertical profiles of the ice cloud microphysical properties. We have tested the performance of the algorithm through numerical simulations for potential sources of such errors as ice crystal orientation, shapes of size distribution, multiple scattering effects to lidar signals, and observational biases in the radar and lidar signals. We applied the retrieval algorithm to the ground-based and shipboard observation data for cirrus clouds, and found a close correlation between effective size and fall velocity of ice crystals. The results from the present study will be useful for improving ice cloud remote sensing and cloud-radiation schemes in climate models. Less

本研究的主要目的是开发一种协同的观察技术来通过结合地面的主动和被动遥感，并验证其对平面卫星型云云雷达和痛苦的有效性，从而检索冰云的微物理和辐射特性，以测量空间中的冰云。我们已经开发了短波（太阳能）和长波（红外）辐射的转移计算方案，用于带有冰云的云大气。通过使用计算方案，我们已经模拟了混合相云和中纬度圆柱云的观察到的辐射特性，并研究了含有冰粒的云的微物理特性与辐射特性之间的关系。一项敏感性研究表明，可以使用在35-GHz和95 GHz处使用双重频率的云雷达来检索混合相云的微物理特性。此外，我们已经开发了三二维族人的准分析溶液……对不均匀气氛的更多辐射转移对等。同质性中显​​示的云的初步计算基本上影响了辐射场，特别是对传播的辐射。这表明，通过传输太阳光线性测量值对云特性的遥远灵敏度不是实行的。我们通过使用与0.532μm处波波长的光学激光相处的95-GHz云雷达，开发了一种新的正向算法，用于检索有效尺寸和冰云的有效尺寸和冰水含量。该算法使我们能够估计冰云微物理特性的垂直轮廓。我们已经通过数值模拟测试了算法的性能，以解决诸如冰晶方向，大小分布的形状，对激光雷达信号的多个散射效应以及雷达和激光雷达信号中的观察偏见等误差的潜在来源。我们将检索算法应用于卷云的地面和船上观察数据，并发现有效尺寸与冰晶速度的降速之间有着密切的相关性。本研究的结果将有助于在气候模型中改善冰云遥感和云辐射方案。较少的

项目成果

H.Okamoto: "Information content of the 95GHz cloud radar siganls : Theoretical assessment of non-sphericity and error evaluation of the discrete dipole approximation"Journal of Geophysical Research. 107・D22 4628. doi:10.1029/2001JD001386 (2002)

H. Okamoto：“95GHz云雷达信号的信息内容：非球形度的理论评估和离散偶极近似的误差评估”地球物理研究杂志107・D22 4628.doi：10.1029/2001JD001386（2002）

S.Asano: "Development of a radiometer-sonde for simultaneously measuring the downward and upward broadband fluxes of shortwave and longwave radiation"Journal of the Meteorological Society of Japan. 82・2(in print). (2004)

S.Asano：“同时测量短波和长波辐射的向下和向上宽带通量的辐射计探空仪的开发”日本气象学会杂志82·2（印刷中）。

S.Asano, A.Uchiyama, A.Yamazaki, J.-F.Gayet, M.Tanizono: "Two case studies of winter continental-type water and mixed-phased stratocumuli over the sea. II : Absorption of solar radiation"Journal of Geophysical Research. 107・D21 4570. doi:10.1029/2001JD001

S.Asano、A.Uchiyama、A.Yamazaki、J.-F.Gayet、M.Tanizono：“冬季大陆型水和海上混合相层积云的两个案例研究。II：太阳辐射的吸收”期刊地球物理研究 107・D21 4570.doi:10.1029/2001JD001

S.Iwasaki: "Analysis of lidar returns from rectangles and hexagonal ice crystals"IRS 2000 : Current Problems in Atmospheric Radiation (Ed. W. L. Smith and Yu. M. Timofeyev), A. Deepak Publishing. 999-1002 (2001)

S.Iwasaki：“激光雷达从矩形和六角形冰晶返回的分析”IRS 2000：大气辐射的当前问题（Ed. W. L. Smith 和 Yu. M. Timofeyev），A. Deepak 出版社。

H.Okamoto: "Information content of the 95-GHz cloud radar signals : Theoretical assessment of effects of nonsphericity and error evolution of the discrete dipole approximation"Journal of Geophysical Research. 107・D22. AAC4-1-AAC4-16 (2002)

H.Okamoto：“95 GHz 云雷达信号的信息内容：离散偶极子近似的非球形影响和误差演化的理论评估”地球物理研究杂志 107・D22（2002 年）。