A Radar Simulator for High-Resolution Nonhydrostatic Models
A Radar Simulator for High-Resolution Nonhydrostatic Models
复制标题
用于高分辨率非静水模型的雷达模拟器
DOI：
10.1175/jtech1905.1
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发表时间：
2006
影响因子：
2.2
通讯作者：
G. Scialom
中科院分区：
文献类型：
--
作者：
O. Caumont;V. Ducrocq;G. Delrieu;M. Gosset;J. Pinty;J. P. D. Chatelet;H. Andrieu;Y. Lemaitre;G. Scialom
在研究非静力中尺度大气模式（Meso-NH）中，开发了一个高分辨率（1-5 km）非静力模式的全雷达模拟器。该模拟器由构建块组成，每个构建块描述特定的物理过程（散射，光束弯曲等）。对于这些区块中的每一个，已经实施了几种公式。例如，雷达模拟器提供了在瑞利、瑞利-甘斯、米氏或T矩阵散射方法中进行选择的可能性，并且波束弯曲可以从有效地球半径导出，或者可以取决于空气折射率的垂直梯度。此外，雷达模拟器是完全一致的微物理参数化所使用的大气数值模式。灵敏度实验进行了使用不同的配置的模拟器。它们允许指定一个观测操作员，用于高分辨率非流体静力数值天气预报系统对雷达反射率的同化，以及用于其验证。2002年9月8日至9日在法国东南部，这是有据可查的体积数据从S-波段雷达的暴洪的研究，用来说明雷达模拟器作为中尺度模型的验证工具的能力。
A full radar simulator for high-resolution (1–5 km) nonhydrostatic models has been developed within the research nonhydrostatic mesoscale atmospheric (Meso-NH) model. This simulator is made up of building blocks, each of which describes a particular physical process (scattering, beam bending, etc.). For each of these blocks, several formulations have been implemented. For instance, the radar simulator offers the possibility to choose among Rayleigh, Rayleigh–Gans, Mie, or T-matrix scattering methods, and beam bending can be derived from an effective earth radius or can depend on the vertical gradient of the refractive index of air. Moreover, the radar simulator is fully consistent with the microphysical parameterizations used by the atmospheric numerical model. Sensitivity experiments were carried out using different configurations for the simulator. They permitted the specification of an observation operator for assimilation of radar reflectivities by high-resolution nonhydrostatic numerical weather prediction systems, as well as for their validation. A study of the flash flood of 8–9 September 2002 in southeastern France, which was well documented with volumetric data from an S-band radar, serves to illustrate the capabilities of the radar simulator as a validation tool for a mesoscale model.