Improved Detection of Severe Storms Using Experimental Fine-Resolution WSR-88D Measurements
Improved Detection of Severe Storms Using Experimental Fine-Resolution WSR-88D Measurements
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使用实验性高分辨率 WSR-88D 测量改进对严重风暴的检测
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
C. Ziegler
中科院分区：
文献类型：
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作者：
Rodger A. Brown;Bradley A. Flickinger;Eddie Forren;David M. Schultz;D. Sirmans;P. Spencer;Vincent T. Wood;C. Ziegler
天气监视雷达-1988多普勒（WSR 88 D）雷达的多普勒速度和反射率测量为预报员提供了重要的输入，因为他们准备发布短期严重风暴和龙卷风警报。雷达收集的海流分辨率数据的方位角间距为1.0°，反射率的距离间距为1.0公里，多普勒速度和频谱宽度的距离间距为0.25公里。为了测试提高数据分辨率的可行性，国家强风暴实验室的试验台WSR-88 D（KOUN）在强雷暴中使用0.5°方位角间距和0.25公里距离间距收集数据，结果反射率分辨率提高了8倍，多普勒速度和频谱宽度分辨率提高了2倍。显示当前分辨率的WSR-88 D多普勒速度和反射率的签名在强烈的风暴进行了比较，显示更精细的分辨率签名。在所有范围内，高分辨率数据提供了更好的描述严重风暴的特点。85%的平均旋转速度来自精细分辨率的中气旋签名比来自当前分辨率签名的速度。同样，龙卷风和龙卷风涡旋特征的多普勒速度差异约有85%强于当前分辨率数据得出的值。此外，使用高分辨率反射率数据更容易探测到低空边界。在100公里以上的范围内，高分辨率反射率显示器显示出强烈的风暴特征，如有界的弱回波区和钩状回波，这在当前分辨率显示器上并不明显。因此，与电流分辨率测量相比，精细分辨率测量的主要优点是能够在WSR-88 D的更大范围内探测到更强的反射率和多普勒速度特征。
Doppler velocity and reflectivity measurements from Weather Surveillance Radar-1988 Doppler (WSR88D) radars provide important input to forecasters as they prepare to issue short-term severe storm and tornado warnings. Current-resolution data collected by the radars have an azimuthal spacing of 1.0° and range spacing of 1.0 km for reflectivity and 0.25 km for Doppler velocity and spectrum width. To test the feasibility of improving data resolution, National Severe Storms Laboratory’s test bed WSR-88D (KOUN) collected data in severe thunderstorms using 0.5°-azimuthal spacing and 0.25-km-range spacing, resulting in eight times the resolution for reflectivity and twice the resolution for Doppler velocity and spectrum width. Displays of current-resolution WSR-88D Doppler velocity and reflectivity signatures in severe storms were compared with displays showing finer-resolution signatures. At all ranges, fine-resolution data provided better depiction of severe storm characteristics. Eighty-five percent of mean rotational velocities derived from fine-resolution mesocyclone signatures were stronger than velocities derived from current-resolution signatures. Likewise, about 85% of Doppler velocity differences across tornado and tornadic vortex signatures were stronger than values derived from current-resolution data. In addition, low-altitude boundaries were more readily detected using fine-resolution reflectivity data. At ranges greater than 100 km, fineresolution reflectivity displays revealed severe storm signatures, such as bounded weak echo regions and hook echoes, which were not readily apparent on current-resolution displays. Thus, the primary advantage of fine-resolution measurements over current-resolution measurements is the ability to detect stronger reflectivity and Doppler velocity signatures at greater ranges from a WSR-88D.