Toward Exploring the Synergy Between Cloud Radar Polarimetry and Doppler Spectral Analysis in Deep Cold Precipitating Systems in the Arctic
Toward Exploring the Synergy Between Cloud Radar Polarimetry and Doppler Spectral Analysis in Deep Cold Precipitating Systems in the Arctic
复制标题
探索北极深冷降水系统云雷达偏振测量与多普勒频谱分析之间的协同作用
DOI：
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发表时间：
2018
期刊：
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通讯作者：
E. Luke
中科院分区：
文献类型：
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作者：
M. Oue;P. Kollias;A. Ryzhkov;E. Luke
北极冰和混合相云的研究是一项具有挑战性的研究，其特征是在相同的云量中存在多种冰颗粒类型。本研究提出了一种新的方法，通过结合Ka波段天顶指向雷达多普勒光谱和Ka/W波段扫描雷达测量的极化雷达变量的准垂直剖面，对北极深降水系统中冰和混合相微物理过程的复杂性进行定性和定量分析。结果表明，在枝晶/平面生长层中经常出现多模态多普勒光谱，在多普勒速度方面，局部生成的，较慢下降的粒子群与较快下降的粒子群分离得很好。较慢下降的粒子群有助于增加差分反射率（ZDR），而在该枝晶生长温度范围内，较慢和较快下降的粒子群都引起了特定差分相（KDP）的增强。多模态多普勒光谱频繁出现的另一个区域是在混合相层中，其中两个种群产生的ZDR和KDP值接近于0，表明存在环化过程。多普勒光谱和极化雷达变量的联合分析提供了对雪形成微物理的重要见解，并允许分离不同习性的冰对反射率和ZDR值的贡献。
The study of Arctic ice and mixed‐phase clouds, which are characterized by a variety of ice particle types in the same cloudy volume, is challenging research. This study illustrates a new approach to qualitative and quantitative analysis of the complexity of ice and mixed‐phase microphysical processes in Arctic deep precipitating systems using the combination of Ka‐band zenith‐pointing radar Doppler spectra and quasi‐vertical profiles of polarimetric radar variables measured by a Ka/W‐band scanning radar. The results illustrate the frequent occurrence of multimodal Doppler spectra in the dendritic/planar growth layer, where locally generated, slower‐falling particle populations are well separated from faster‐falling populations in terms of Doppler velocity. The slower‐falling particle populations contribute to an increase of differential reflectivity (ZDR), while an enhanced specific differential phase (KDP) in this dendritic growth temperature range is caused by both the slower and faster‐falling particle populations. Another area with frequent occurrence of multimodal Doppler spectra is in mixed‐phase layers, where both populations produce ZDR and KDP values close to 0, suggesting the occurrence of a riming process. Joint analysis of the Doppler spectra and the polarimetric radar variables provides important insight into the microphysics of snow formation and allows the separation of the contributions of ice of different habits to the values of reflectivity and ZDR.