Regional variability of summertime raindrop size distribution from a network of disdrometers in Beijing
Regional variability of summertime raindrop size distribution from a network of disdrometers in Beijing
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北京夏季雨滴尺寸分布的区域变异性
DOI：
10.1016/j.atmosres.2021.105591
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发表时间：
2021
影响因子：
5.5
通讯作者：
Yong Zhang
中科院分区：
文献类型：
--
作者：
Yi Han;Jianping Guo;Yuxing Yun;Jian Li;Xiaoran Guo;Yanmin Lv;Ding Wang;Lin Li;Yong Zhang
由于缺乏观测，人们对区域雨滴尺寸分布（DSD）特征知之甚少。本文利用 2017 年 4 月至 9 月 10 个测速仪站点的 DSD 观测数据，研究了北京夏季 DSD 的区域变化。分析了对流降水和层状降水的 DSD 特征，主要按降雨率 (R) 进行分类。层状降水和对流降水的形状 (μ) 和斜率 (λ) 参数均遵循二级多项式回归关系。平均而言，层状降水具有比对流降水更大的μ和λ值，而对流降水具有更大的质量加权平均直径（Dm）和广义截距参数（Nw）。有趣的是，北京北部的 μ 和 λ 值较大，而南方的 Dman 和 Nw 值较大，这可能是由于地形差异所致。还分析了降雨率对 DSD 的依赖性。一般来说，Dm-R和Nw-R关系服从幂律分布，并且Dman和N都随着R的增加而显着增加。随着降雨率的增加，Dm 不断增加到 1.5 毫米左右，直到达到平衡状态。该研究结果可为利用遥感技术更好地估算降雨量提供有益的参考。
Regional raindrop size distribution (DSD) features are poorly understood due to the lack of observations. Here we investigate the regional variability of summertime DSD in Beijing, using the DSD observations from ten disdrometer sites from April to September 2017. The characteristics of DSD are analyzed for both convective and stratiform precipitation, mainly classified by rain rate (R). The shape (μ)and slope (λ)parameters follow a second-degree polynomial regression relationship for both stratiform and convective precipitation. On average, stratiform precipitation is found to have larger values ofμandλthan convective precipitation, whereas convective precipitation has a larger mass-weighted mean diameter (Dm) and a generalized intercept parameter (Nw). Interestingly, the north of Beijing has larger values ofμandλ, as opposed toDmandNwthat exhibit greater values in the south, which could probably be attributed to terrain differences. The rain rate dependence on DSD is analyzed as well. In general, theDm-RandNw-Rrelationships follow a power-law distribution, and bothDmandNwincrease significantly withR. As the rain rate increases,Dmkeeps increasing to around 1.5 mm until an equilibrium state is reached. The findings obtained here could provide useful reference for better estimations of rainfall using the remote sensing techniques.