Dual-Wavelength Polarimetric Radar Analyses of Tornadic Debris Signatures
Dual-Wavelength Polarimetric Radar Analyses of Tornadic Debris Signatures
复制标题
龙卷碎片特征的双波长偏振雷达分析
DOI：
10.1175/jamc-d-13-0189.1
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发表时间：
2014
影响因子：
3
通讯作者：
Guifu Zhang
中科院分区：
文献类型：
--
作者：
D. Bodine;R. Palmer;Guifu Zhang
摘要：使用 S 和 C 波段极化雷达数据研究龙卷风碎片特征 (TDS) 的统计特性，并与损害调查和卫星图像进行比较。雷达与 2010 年 5 月 10 日俄克拉荷马州摩尔-俄克拉荷马城的龙卷风非常接近，该龙卷风在增强型藤田等级 (EF4) 上被评为 4 级，提供了大量的分辨率体积，以及用于双波长比较的良好时间和空间匹配。这些比较表明，S 波段 TDS 比 C 波段 TDS 表现出更高的雷达反射率因子 (ZHH) 和共极互相关系数 (ρhv)。由于碎片的电尺寸较小，因此非瑞利散射体与总散射体的比例较小，从而降低了共振效应，因此较高的 S 波段 ρhv 可能会产生。当龙卷风经过大片水域附近的植被区域时，在 S 和 C 波段 350 m AGL 处观察到负 ZDR 特征。另一个有趣的特征是传播的正（负）转变......
AbstractStatistical properties of tornado debris signatures (TDSs) are investigated using S- and C-band polarimetric radar data with comparisons to damage surveys and satellite imagery. Close proximity of the radars to the 10 May 2010 Moore–Oklahoma City, Oklahoma, tornado that was rated as a 4 on the enhanced Fujita scale (EF4) provides a large number of resolution volumes, and good temporal and spatial matching for dual-wavelength comparisons. These comparisons reveal that S-band TDSs exhibit a higher radar reflectivity factor (ZHH) and copolar cross-correlation coefficient (ρhv) than do C-band TDSs. Higher S-band ρhv may result from a smaller ratio of non-Rayleigh scatterers to total scatterers due to the smaller electrical sizes of debris and, consequently, reduced resonance effects. A negative ZDR signature is observed at 350 m AGL at both the S and C bands as the tornado passes over a vegetated area near a large body of water. Another interesting signature is a positive (negative) shift in propagati...