Extension of a Multisensor Satellite Radiance-Based Evaluation for Cloud System Resolving Models
Extension of a Multisensor Satellite Radiance-Based Evaluation for Cloud System Resolving Models
复制标题
基于多传感器卫星辐射度的云系统解析模型评估的扩展
DOI：
10.2151/jmsj.2018-002
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发表时间：
2018
影响因子：
3.1
通讯作者：
M. Satoh
中科院分区：
文献类型：
--
作者：
W. Roh;M. Satoh
作为一种替代方法，以前的多传感器卫星评估的云系统解决模式（CSRMs），一种技术的CSRMs的海洋降水云使用组合红外和微波通道。该方法利用红外11 μm和高频微波（89.0GHz）亮温（TBs）的云顶温度和冰散射定量分析降水云。低频（18.7 GHz）的TB阈值用于识别降水区域。这种方法扩展了以前的方法的基础上，热带降雨测量使命（TRMM）降水雷达，使用一个狭窄的覆盖范围，通过将广泛的被动微波传感器扫描带和冰云的敏感性。用这种方法对非静力二十面体大气模式NICAM的两种云微物理方案的数值结果进行了热带公海的检验。在这两个模拟在89.0 GHz的散射强度是不同的，由于参数化的雪和霰的大小分布。双峰雪的大小分布改善了TB低估在89.0 GHz。这些结果表现出类似的结构，使用以前的方法产生的云顶温度和降水顶高度的联合直方图，高估散射强度的频率在这项研究中，高降水顶高度的频率在以前的研究中超过12公里。据观察，在云微物理方案中的雪的大小分布的变化可以导致更好的协议，在89.0 GHz的模拟TB。此外，我们使用卫星模拟器研究了非球形雪假设的影响。辐射传输模型中的非球形雪形状的影响导致了在89.0 GHz的TB的较小变化相比，没有非球形假设的两个模拟的TB之间的差异。
As an alternative approach to previous multisensor satellite evaluations for cloud system resolving models (CSRMs), a technique for precipitation clouds over the ocean of CSRMs is presented using combined infrared and microwave channels. This method quantitatively analyzes precipitation clouds using cloud-top temperatures and ice scatterings from infrared 11 μm and high frequency microwave (89.0 GHz) brightness temperatures (TBs). The TB threshold at low frequencies (18.7 GHz) is used to identify precipitation regions. This method extends a previous approach based on tropical rainfall measuring mission (TRMM) precipitation radar which uses a narrow coverage, by incorporating a wide passive microwave sensor swath and ice cloud sensitivity. The numerical results of the non-hydrostatic icosahedral atmospheric model, NICAM, with two cloud microphysics schemes were evaluated over the tropical open ocean using this method. The scattering intensities in both simulations at 89.0 GHz were different due to the parameterizations of the snow and graupel size distributions. A bimodal snow size distribution improved the TB underestimation at 89.0 GHz. These results exhibited similar structures to the joint histograms of cloud-top temperatures and precipitation-top heights generated using the previous method; the frequencies of overestimated scattering intensities in this study and the frequencies of high precipitation-top heights above 12 km in the previous study. It was observed that the change in the snow size distribution in the cloud microphysics scheme can lead to better agreements of simulated TBs at 89.0 GHz. Furthermore, we investigated the impacts of nonspherical snow assumptions using a satellite simulator. The effect of a nonspherical snow shape in the radiative transfer model caused a smaller change in TBs at 89.0 GHz compared to the difference between the TBs of the two simulations without nonspherical assumptions.