Differences in the Ice Particle Shattering Impact on the CIP Measurements in the Stratiform Cloud Region and the Embedded Convection Region
Differences in the Ice Particle Shattering Impact on the CIP Measurements in the Stratiform Cloud Region and the Embedded Convection Region
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DOI：
10.3390/w13172322
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发表时间：
2021-08
期刊：
影响因子：
3.4
通讯作者：
Minsong Huang
中科院分区：
文献类型：
--
作者：
Minsong Huang
对流单体嵌入层状云是一种重要的降水系统。精确了解云的微物理结构对于发展数值天气预报模式和人工增雨是有用的。航空测量是确定云微物理结构的重要手段之一。然而，在测量过程中，云粒子破碎的云的微物理特性的测量提出了一个严重的问题。为了研究层状云区和对流云区碎冰对标准云成像探测器（CIP）测量的不同影响，提出了一种识别碎冰的时变阈值方法。应用该算法对破碎碎片进行了识别，分析了破碎碎片对颗粒粒径分布、颗粒数浓度和冰水含量测量的影响。结果表明，在层状区和对流区，粒径小于400 μm时，破碎效应随粒径的增大而减小，粒径在400 ~ 1000 μm之间波动，粒径大于1000 μm时，破碎效应略有增大。然而，对流云的PSD未修正与经破碎事件修正后的PSD的平均比值在整个尺度上大于层状云，在小于1000 μm的尺度上是层状云的近2倍。在层状区域，测得的数浓度平均可被高估3.9倍，而在对流区域，它是7.7，几乎是层状区域的两倍。在层状区，平均可高估29.5%的冰水含量，而在对流区，可高估60.7%。这些发现有助于云物理学界将机载CIP测量数据用于数值天气和气候模式。
Stratiform clouds with embedded convective cells is an important precipitation system. Precise knowledge of the cloud’s microphysical structure can be useful for the development of a numerical weather prediction model and precipitation enhancement. Airborne measurement is one of the important ways for determining the microphysical structure of clouds. However, cloud particle shattering during measurement poses a serious problem to the measured microphysical characterization of clouds. In order to study the different influences of the shattered ice particles on the standard cloud imaging probe (CIP) measurement in the stratiform cloud region and the convective cloud region, a time-variant threshold method to identify the shattered fragments is presented. After application of this algorithm, the shattered fragments were recognized and their impacts on the particle size distribution (PSD), particle number concentration and ice water content measurement were analyzed. It was found that the shattering effect on the PSD decreases with the increasing size of less than 400 μm, fluctuates between 400 μm and 1000 μm and slightly increases with the increasing size of larger than 1000 μm on average in a stratiform region and a convective region. However, the average ratio of PSD uncorrected to that corrected for shattering events using the presented algorithm in convective clouds is larger than that in the stratiform regions in the whole size, and nearly twice that in the size of less than 1000 μm. The measured number concentration can be overestimated by up to a factor of 3.9 on average in a stratiform region, while in a convective region, it is 7.7, nearly twice that of a stratiform region. The ice water content in a stratiform region can be overestimated by 29.5% on average, but by 60.7% in a convective region. These findings can be helpful for the cloud physics community to use the airborne CIP measurement data for numerical weather and climate models.