A 35-GHz polarimetrie Doppler radar and its application for observing clouds associated with Typhoon Nuri
A 35-GHz polarimetrie Doppler radar and its application for observing clouds associated with Typhoon Nuri
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DOI：
10.1007/s00376-010-0073-5
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发表时间：
2011-06
影响因子：
5.8
通讯作者：
L. Zhong;Liping Liu;S. Feng;Runsheng Ge;Zhe Zhang
中科院分区：
文献类型：
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作者：
L. Zhong;Liping Liu;S. Feng;Runsheng Ge;Zhe Zhang
毫米波雷达已被证明是云观测和研究的有效工具。本研究首次利用具有多普勒和偏振功能的8毫米波段云雷达（MMCR）对中国的云动力学进行了研究。本文讨论了它的设计、系统性能、定标以及在台风云测量中的应用。利用云雷达测量的雷达反射率（Z）、多普勒速度（Vr）、速度谱宽度（Sw）和垂直入射时的退偏振比（LDR），分析了2008年8月台风“努里”造成的云系和降水的微物理和动力过程。结果表明，MMCR观测的反射率与邻近的中国S波段新一代天气雷达（SA）的回波高度和融化层位置资料基本一致，但Ka波段MMCR比SA雷达提供了更详细的云结构信息和弱降水资料。雷达反射率和LDR在垂直结构上的变化反映了粒子相态由冰向水的转变。MMCR观测的垂直速度和速度谱宽度表明，层状云层中存在上升气流和强湍流。MMCR为我国气象研究提供了一种有价值的新技术。
Millimeter-wavelength radar has proved to be an effective instrument for cloud observation and research. In this study, 8-mm-wavelength cloud radar (MMCR) with Doppler and polarization capabilities was used to investigate cloud dynamics in China for the first time. Its design, system specifications, calibration, and application in measuring clouds associated with typhoon are discussed in this article. The cloud radar measurements of radar reflectivity (Z), Doppler velocity (Vr), velocity spectrum width (Sw) and the depolarization ratio (LDR) at vertical incidence were used to analyze the microphysical and dynamic processes of the cloud system and precipitation associated with Typhoon Nuri, which occurred in southern China in August 2008. The results show the reflectivity observed using MMCR to be consistent with the echo height and the melting-layer location data obtained by the nearby China S-band new-generation weather radar (SA), but the Ka-band MMCR provided more detailed structural information about clouds and weak precipitation data than did the SA radar. The variation of radar reflectivity andLDRin vertical structure reveals the transformation of particle phase from ice to water. The vertical velocity and velocity spectrum width of MMCR observations indicate an updraft and strong turbulence in the stratiform cloud layer. MMCR provides a valuable new technology for meteorological research in China.