The relationship ( $$\varvec{Z} = \varvec{AR}^{\varvec{b}}$$ Z = AR b ) between radar reflectivity factor, $$\varvec{ Z }$$ Z and rainfall rate, $$\varvec{R }$$ R is studied using the micro rain radar (MRR) observation located over Darjeeling (27.05° N, 88.26° E, 2194 m above the msl) in the foothills of the eastern Himalayan Mountains during Indian summer monsoon and post monsoon seasons (June–October) 2013. Observations from MRR are classified mainly into two types, stratiform and convective, based on the bright band and non-bright band signatures in the radar reflectivity, respectively. We have observed 12 and 7 cases for the stratiform convective rain events, respectively. In the present study MRR is operated mostly during low intensity rainfall rate (0.02–20 mm/h). During southwest monsoon season $$\varvec{Z} {-} \varvec{R }$$ Z - R relation for the stratiform and convective rainfall types are found to be $$\varvec{Z} = 272\varvec{R}^{1.78}$$ Z = 272 R 1.78 and $$\varvec{Z} = 192\varvec{R}^{1.54}$$ Z = 192 R 1.54 respectively. $$\varvec{Z} {-} \varvec{R }$$ Z - R relation for both stratiform and convective rain shows high temporal variation during different months of monsoon and post monsoon seasons. The coefficient $$\varvec{A}$$ A varies between 225 and 289 for stratiform rain and between 153 and 235 for convective rain. The exponent $$\varvec{b}$$ b varies between 1.4 and 2.1 for stratiform rain while between 1.2 and 1.8 for convective rain. Interestingly, we observed a distinct relation with smaller values of $$\varvec{A}$$ A and $$\varvec{b}$$ b for convective rain than stratiform rain over Darjeeling. The height dependence of $$\varvec{A}$$ A and $$\varvec{b}$$ b are also studied which is found to be very small up to ~ 1.5 km above the surface for both types of the precipitating systems.

中文翻译：

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使用微雨雷达 (MRR-2) 在大吉岭（北纬 27.05°，东经 88.26°）上观测到的 Z-R 关系特征：喜马拉雅东部的一个复杂地形区

雷达反射系数、$$\varvec{ Z }$$ Z 与降雨率之间的关系（ $$\varvec{Z} = \varvec{AR}^{\varvec{b}}$$ Z = AR b ）， $$\varvec{R }$$ R 是在印度夏季使用位于喜马拉雅山脉东部山麓的大吉岭（北纬 27.05°，东经 88.26°，海拔 2194 m）上空的微雨雷达 (MRR) 观测进行研究的2013 年季风和后季风季节（6 月至 10 月）。MRR 的观测主要分为两种类型，层状和对流，分别基于雷达反射率中的亮带和非亮带特征。我们分别观测到 12 次和 7 次层状对流雨事件。在本研究中，MRR 主要在低强度降雨率（0.02-20 毫米/小时）期间运行。在西南季风季节 $$\varvec{Z} {-} \varvec{R }$$ Z - R 层状和对流降雨类型的关系被发现为 $$\varvec{Z} = 272\varvec{R} ^{1.78}$$ Z = 272 R 1.78 和 $$\varvec{Z} = 192\varvec{R}^{1.54}$$ Z = 192 R 1.54。$$\varvec{Z} {-} \varvec{R }$$ Z - 层状雨和对流雨的 R 关系在季风和后季风季节的不同月份显示出很大的时间变化。系数 $$\varvec{A}$$ A 对于层状雨在 225 和 289 之间变化，对于对流雨在 153 和 235 之间变化。指数$$\varvec{b}$$b 的层状雨在 1.4 和 2.1 之间变化，而对流雨在 1.2 和 1.8 之间变化。有趣的是，我们观察到对流雨的 $$\varvec{A}$$ A 和 $$\varvec{b}$$ b 的值与大吉岭上空的层状雨有明显的关系。