Dual-frequency radar Doppler spectral retrieval of rain drop size distributions and entangled dynamics variables
Dual-frequency radar Doppler spectral retrieval of rain drop size distributions and entangled dynamics variables
复制标题
双频雷达多普勒谱反演雨滴尺寸分布和纠缠动力学变量
DOI：
10.1002/2014jd023023
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Tridon F
中科院分区：
文献类型：
--
作者：
Tridon F
提出了一种基于Ka-W波段双波长多普勒谱的新技术，用于同时反演雨滴谱和大气状态参数，如湍流和风切变引起的垂直风和大气增宽。该方法的基本原理在于利用由散射和吸收特性的波长依赖性引起的多普勒光谱中观察到的特有特征。一项基于二维视频多普勒仪测量的大数据集的概念性研究表明，对于小/中等空气增宽光谱宽度和平均体积直径超过至少1 mm时，检索性能最佳。检索也仅限于云底以下的范围，并且两个雷达的信噪比超过10 dB，这排除了受强衰减影响的区域。一般来说，它适用于降雨率约为1至30 mm h−1。在大气辐射测量南部大平原网站的初步检索观察显示非常好的协议与独立的反射率测量从0.915 GHz的风廓线。所提出的方法显示出很大的潜力，在降雨研究中的微观物理动力学。
A novel technique based on Ka‐W band dual‐wavelength Doppler spectra has been developed for the simultaneous retrieval of binned rain drop size distributions (DSD) and air state parameters like vertical wind and air broadening caused by turbulence and wind shear. The rationale underpinning the method consists in exploiting the peculiar features observed in Doppler spectra caused by the wavelength dependence of scattering and absorption properties. A notional study based on a large data set of DSDs measured by a two‐dimensional video disdrometer demonstrates that the retrieval performs best for small/moderate air broadening spectral width and when mean volume diameters exceed at least 1 mm. The retrieval is also limited to ranges below cloud base and where the signal‐to‐noise ratio of both radars exceed 10 dB, which rules out regions affected by strong attenuation. Broadly speaking, it is applicable to rain rates comprised between roughly 1 and 30 mm h−1. Preliminary retrieval for observations at the Atmospheric Radiation Measurement Southern Great Plains site shows very good agreement with independent reflectivity measurements from a 0.915 GHz wind profiler. The proposed methodology shows great potential in linking microphysics to dynamics in rainfall studies.