The Measured Relationship between Ice Water Content and Cloud Radar Reflectivity in Tropical Convective Clouds
The Measured Relationship between Ice Water Content and Cloud Radar Reflectivity in Tropical Convective Clouds
复制标题
热带对流云中冰水含量与云雷达反射率的实测关系
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
M. Weber
中科院分区：
文献类型：
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作者：
A. Protat;J. Delanoë;J. Strapp;E. Fontaine;D. Leroy;A. Schwarzenboeck;L. Lilie;C. Davison;F. Dezitter;A. Grandin;M. Weber
在本文中，我们使用前所未有的散装测量的冰水含量（IWC）高达约5克-3和95 GHz的雷达反射率（Z95）来分析这两个数量之间的统计关系及其变化。这项研究的独特之处在于，这些IWC - Z95关系不使用云微物理或后向散射计算的假设。IWC大于2 gm-3也首次包括在这种分析中，由于改进的散装IWC探测技术和针对高冰水含量的飞行计划。使用一个单一的IWC - Z95关系允许IWC从雷达反射率检索小于30%的偏差和40-70%的均方根差。利用这种关系的温度变化性，这些误差可以在整个IWC万国表范围内进一步降低至10-20%的偏差。当Z95> 15-16 dBZ时，IWC误差大大增加，这是由于非瑞利散射效应使IWC - Z95关系失真。提出了一种非线性关系，以将这些误差降低到20%的偏差和20-35%的均方根差。对于对流廓线，这种非线性关系也优于随温度变化的IWC - Z95关系。深热带对流核心内部和周围IWC和温度的联合频率分布表明，在-50 ° C ± 5°C的水平-许多商用喷气式飞机的巡航高度-IWC大于1.5 gm-3只出现在对流廓线中。
In this paper we use unprecedented bulk measurements of ice water content (IWC) up to approximately 5 gm-3 and 95 GHz radar reflectivities (Z95) to analyze the statistical relationship between these two quantities and its variability. The unique aspect of this study is that these IWC – Z95 relationships do not use assumptions on cloud microphysics or backscattering calculations. IWCs greater than 2 gm-3 are also included for the first time in such analysis, owing to improved bulk IWC probe technology and a flight program targeting high ice water content. Using a single IWC – Z95 relationship allows for the retrieval of IWC from radar reflectivities with less than 30% bias and 40-70% rms difference. These errors can be reduced further down to 10-20% bias over the whole IWC range using the temperature variability of this relationship. IWC errors largely increase for Z95> 15-16 dBZ, due to the distortion of the IWC – Z95 relationship by non-Rayleigh scattering effects. A non-linear relationship is proposed to reduce these errors down to 20% bias and 20-35% rms differences. This non-linear relationship also outperforms the temperature-dependent IWC – Z95 relationship for convective profiles. The joint frequency distribution of IWC and temperature within and around deep tropical convective cores shows that at the -50°C ± 5°C level – the cruise altitude of many commercial jet aircraft – IWCs greater than 1.5 gm-3 were found exclusively in convective profiles.
影响因子：
3
作者：
A. Protat;J. Delanoë;D. Bouniol;A. Heymsfield;A. Bansemer;P. Brown
通讯作者：
A. Protat;J. Delanoë;D. Bouniol;A. Heymsfield;A. Bansemer;P. Brown
使用 CloudSat 和 CALIPSO 数据评估 ECMWF 和英国气象局模型中的冰云表示
影响因子：
8.9
作者：
Delanoë J
通讯作者：
Delanoë J
影响因子：
4.4
作者：
Delanoe, Julien;Hogan, Robin J.
通讯作者：
Hogan, Robin J.