Degradation of Radar Reflectivity by Cloud Attenuation at Microwave Frequency
Degradation of Radar Reflectivity by Cloud Attenuation at Microwave Frequency
复制标题
微波频率云衰减导致雷达反射率下降
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
H. Sauvageot
中科院分区：
文献类型：
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作者：
O. Pujol;J. Georgis;L. Feral;H. Sauvageot
摘要本文的主要目的是强调云凝结的大气水的非沉淀成分，可以产生一个强大的衰减在工作微波频率，虽然他们提出了一个低反射率，防止他们的雷达检测。通过一个简单和现实的模式，模拟雷达观测通过温暖的降水目标，从而量化云衰减。模拟关注的机载雷达面向下，并观察降水在四个频率：3，10，35，和94千兆赫。首先考虑两种情况：一个对流单体（强积云加雨）和一个层状（雨层云加毛毛雨）叠加在前一个。其他模拟，然后进行不同类型的积云（congestus，Epherris，和humilis），其特征在于，在微物理意义上，由它们的最大液态水含量的各种厚度。模拟证实了低积云反射率范围从-45 dBZ.
Abstract The main object of this paper is to emphasize that clouds—the nonprecipitating component of condensed atmospheric water—can produce a strong attenuation at operational microwave frequencies, although they present a low reflectivity preventing their radar detection. By way of a simple and realistic model, simulations of radar observations through warm precipitating targets are thus presented in order to quantify cloud attenuation. Simulations concern an airborne radar oriented downward and observing precipitation at four frequencies: 3, 10, 35, and 94 GHz. Two cases are first considered: a convective cell (vigorous cumulus congestus plus rain) and a stratiform one (nimbostratus plus drizzle) superimposed on the previous one. Other simulations are then performed on different types of cumulus (congestus, mediocris, and humilis) with various thicknesses characterized, in a microphysical sense, by their maximum liquid water content. Simulations confirm the low cumulus reflectivity ranging from −45 dBZ...