Triple‐Frequency Doppler Retrieval of Characteristic Raindrop Size
Triple‐Frequency Doppler Retrieval of Characteristic Raindrop Size
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特征雨滴尺寸的三频多普勒反演
DOI：
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发表时间：
2020
影响因子：
3.1
通讯作者：
José Dias Neto
中科院分区：
文献类型：
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作者：
Kamil Mróz;A. Battaglia;S. Kneifel;L. D’Adderio;José Dias Neto
基于三频垂直多普勒雷达测量的特征雨滴尺寸和雨滴尺寸分布宽度（DSD）的反演。该算法利用了一种统计关系，将X和Ka以及Ka和W波段的差分多普勒速度的测量值映射到上述两个DSD矩中。统计映射建立在7，900小时的多普勒仪观测的DSD及其模拟多普勒速度上。此外，还提出了一种仅基于DDVX-W测量的Dm检索，并将其性能与利用DDVKa-W数据的类似算法进行了比较。使用最近在Juelich Observatory for Cloud Evolution（德国JOYCE）举行的现场活动中收集的三频雷达数据对检索进行了测试，其中DSD的现场测量距离垂直指向的雷达只有几米远。三频率检索能够获得Dm，对于Dm范围为0.7至2.4 mm，不确定度低于25%。与先前发表的双频检索相比，第三频率并没有改善小Dm（<1.4 mm）的检索。然而，对于较大的Dm，它明显优于DDVKa−W算法（2.25 mm处的20%与50%偏差）。同样与DDVX−W方法相比，发现三频反演在Dm=2.25 mm的偏差方面提供了15%的改进。对于0.2 mm，三频反演σm的不确定性为20-50%。
A retrieval for characteristic raindrop size and width of the drop size distribution (DSD) based on triple‐frequency vertical Doppler radar measurements is developed. The algorithm exploits a statistical relation that maps measurements of the differential Doppler velocities at X and Ka and at Ka and W bands into the two aforementioned DSD moments. The statistical mapping has been founded on 7,900 hr of disdrometer‐observed DSDs and their simulated Doppler velocities. Additionally, a retrieval of Dm based only on DDVX−W measurements is also presented, and its performance is compared to the analogous algorithm exploiting DDVKa−W data. The retrievals are tested using triple‐frequency radar data collected during a recent field campaign held at the Juelich Observatory for Cloud Evolution (JOYCE, Germany) where in situ measurements of the DSD were carried out only few meters away from the vertically pointing radars. The triple‐frequency retrieval is able to obtain Dm with an uncertainty below 25% for Dm ranging from 0.7 to 2.4 mm. Compared to previously published dual‐frequency retrievals, the third frequency does not improve the retrieval for small Dm ( <1.4 mm). However, it significantly surpasses the DDVKa−W algorithm for larger Dm (20% versus 50% bias at 2.25 mm). Also compared to DDVX−W method, the triple‐frequency retrieval is found to provide an improvement of 15% in terms of bias for Dm=2.25 mm. The triple‐frequency retrieval of σm performs with an uncertainty of 20–50% for 0.2
改进冬季降水过程观测的三频偏振雷达实验
影响因子：
11.4
作者：
Dias Neto;S. Kneifel;D. Ori;S. Trömel;J. Handwerker;B. Bohn;K. Mühlbauer;M. Lenefer;C. Simmer
通讯作者：
C. Simmer