Impact of Wind Direction, Wind Speed, and Particle Characteristics on the Collection Efficiency of the Double Fence Intercomparison Reference
Impact of Wind Direction, Wind Speed, and Particle Characteristics on the Collection Efficiency of the Double Fence Intercomparison Reference
复制标题
风向、风速和颗粒特征对双栅比对参考采集效率的影响
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
L. Lanza
中科院分区：
文献类型：
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作者：
J. Thériault;R. Rasmussen;E. Petro;J. Trépanier;M. Colli;L. Lanza
降雪的精确测量在气候变率、交通运输、水资源等研究领域具有重要意义。一个主要的问题是，降雪测量很困难，可能会导致严重的误差。例如，大多数仪表屏蔽结构的收集效率通常随着风速的增加而降低。此外，对于给定的风速，可以观察到很大的散射，这被认为是由雪花的类型引起的。此外，收集效率在很大程度上取决于用于校正数据的参考资料，通常是世界气象组织推荐的双栅栏相互比较参考（DFIR）。本研究的目的是评估天气条件对DFIR收集效率的影响。请注意，DFIR被定义为放置在双围栏中的手动仪表。然而，在这项研究中，只有双栅栏被调查，同时仍然被称为DFIR。为了解决这一问题，利用计算流体力学对DFIR附近的流场进行了详细的分析。获得粒子轨迹，计算不同风速下不同降水类型的收集效率。结果表明：到达DFIR中心的降水量可超过实际降水量的100%，且与雪花类型、风速和风向有关；总的来说，这项研究有助于更好地理解与使用DFIR作为测量降雪的参考标准相关的不确定性来源。
The accurate measurement of snowfall is important in various fields of study such as climate variability, transportation, and water resources. A major concern is that snowfall measurements are difficult and can result in significant errors. For example, collection efficiency of most gauge–shield configurations generally decreases with increasing wind speed. In addition, much scatter is observed for a given wind speed, which is thought to be caused by the type of snowflake. Furthermore, the collection efficiency depends strongly on the reference used to correct the data, which is often the Double Fence Intercomparison Reference (DFIR) recommended by the World Meteorological Organization. The goal of this study is to assess the impact of weather conditions on the collection efficiency of the DFIR. Note that the DFIR is defined as a manual gauge placed in a double fence. In this study, however, only the double fence is being investigated while still being called DFIR. To address this issue, a detailed analysis of the flow field in the vicinity of the DFIR is conducted using computational fluid dynamics. Particle trajectories are obtained to compute the collection efficiency associated with different precipitation types for varying wind speed. The results show that the precipitation reaching the center of the DFIR can exceed 100% of the actual precipitation, and it depends on the snowflake type, wind speed, and direction. Overall, this study contributes to a better understanding of the sources of uncertainty associated with the use of the DFIR as a reference gauge to measure snowfall.