A Comparison of the Polarimetric Radar Characteristics of Heavy Rainfall From Hurricanes Harvey (2017) and Florence (2018)
A Comparison of the Polarimetric Radar Characteristics of Heavy Rainfall From Hurricanes Harvey (2017) and Florence (2018)
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DOI：
10.1029/2019jd032212
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发表时间：
2020-05
期刊：
影响因子：
--
通讯作者：
Jennifer C. DeHart;M. Bell
中科院分区：
文献类型：
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作者：
Jennifer C. DeHart;M. Bell
偏光层雷达数据用于比较飓风哈维（Harvey）的降雨特征（2017年）和佛罗伦萨（2018）由于循环中心的陆上流下山长期，在沿海地区的博蒙特（Beaumont）沿线的海岸最大化Harvey中的雷达观察表明，与先前的热带气旋研究一致的高浓度的小型至中等滴剂的占主导地位。 8月28日和30日。降低的变异性，较少的反射率和差异反射率，高浓度和中等大小的降低的频率表明，佛罗伦萨与Harvey相比，佛罗伦萨的覆盖率降低了。 Decaya速率和垂直风剪切产生了在Harvey和Florence中看到的独特的降水结构和微物理差异。
Polarimetric coastal radar data are used to compare the rainfall characteristics of Hurricanes Harvey (2017) and Florence (2018). Intense rainfall was an infrequent yet important contributor to the total rainfall in Harvey, but its relative contribution varied spatially. The total rainfall over land maximized near the coast over Beaumont, TX, due to intense convection resulting from prolonged onshore flow downshear from the circulation center. Overall, polarimetric radar observations in Harvey show a dominance of high concentrations of small‐to‐medium drops, consistent with prior tropical cyclone studies. The microphysical characteristics were spatially and temporally inhomogeneous however, with larger drops more frequent on 27 August and higher number concentrations more frequent on 28 and 30 August. The polarimetric variables and raindrop characteristics observed during Florence share broad similarities to Harvey, but had reduced variability, fewer observations of stronger reflectivity and differential reflectivity, and a lower frequency of high number concentrations and medium‐sized drops. The radar data indicate Florence had reduced coverage of stronger convection compared to Harvey. We hypothesize that differences in storm motion, intensity decay rates, and vertical wind shear produce the distinct precipitation structures and microphysical differences seen in Harvey and Florence.