大气科学2025，Vol.49Issue(4)：1080-1097,18.DOI:10.3878/j.issn.1006-9895.2403.23134
青藏高原东南部一次典型降水性层状云的水凝物分类和过冷液态水含量分布特征
Distribution Characteristics of Hydrometeor Classification and Supercooled Liquid Water Content for a Typical Precipitating Stratiform Cloud on the Southeastern Qinghai-Xizang Plateau
摘要
Abstract
The distribution characteristics of hydrometeor and supercooled liquid water in clouds are crucial for understanding the microphysical mechanisms behind cloud and precipitation formation,as well as for constructing and validating numerical model cloud physics parameterization schemes.On the basis of Ka-band radar data collected during the Second Qinghai-Xizang Plateau Scientific Expedition in Nyingchi,southeast Qinghai-Xizang Plateau,the distribution properties of hydrometeor classification and supercooled liquid water content of a typical precipitating stratiform cloud(on 16-17 September 2019)were investigated following data quality control procedures.The results showed that the data denoising rate of the cloud radar based on the"k-nearest neighbor frequency method"was within the range of 1.5%-5.0%,and the data gap filling rate was within the range of 3.5%-7.0%.After applying the iterative correction method,the difference between the attenuation-corrected radar data and raw data was between 0 and 5 dBZ.The precipitation formation mechanism for this typical stratiform cloud had certain unique characteristics.Precipitation was formed by the merging of middle and high clouds induced by the lifting of large-scale atmospheric circulation,and low-level clouds were formed by orographic lifting.In the initial stage,the cloud top reached 12 km,and the clouds at the upper and lower levels were distinctly separated.There was no evident bright band at the melting layer.The particle distribution within the clouds was relatively homogeneous,and ice crystals and snow particles were dominant,with a relatively high supercooled liquid water content in the middle and high clouds.In the mature stage,the middle and high clouds merged with the low clouds,leading to precipitation formation,and the cloud tops decreased to around 10 km.The clouds became inhomogeneous,with an evident bright band at the melting layer and weakly embedded convective cells.The dominant hydrometeors were ice and snow particles,with a small amount of graupel in the embedded convective cells.The supercooled liquid water content was mainly distributed in the embedded convective cells,with a maximum value of 0.5-0.6 g m-3.In the decaying stage,as the large-scale weather system passed over the study region,the middle and high cold clouds weakened rapidly,and the weak warm rain generated by the low-level orographic clouds became dominant,resulting in the disappearance of the bright band at the melting layer.A thin layer of ice and snow was present above the melting layer.关键词
Ka云雷达/降水性层状云/水凝物分类/液态水含量/青藏高原东南部Key words
Ka-band cloud radar/Precipitating stratiform clouds/Hydrometeor classification/Liquid water content/Southeastern Qinghai-Xizang Plateau分类
天文与地球科学引用本文复制引用
谭杰,付丹红,郭学良,樊昌元,苏德斌..青藏高原东南部一次典型降水性层状云的水凝物分类和过冷液态水含量分布特征[J].大气科学,2025,49(4):1080-1097,18.基金项目
科技部第二次青藏高原科学考察——极端天气气候事件与灾害风险项目 2019QZKK0104,四川省科学技术厅项目 2024YFHZ 0151 The Second Tibetan Plateau Scientific Expedition—Extreme Weather and Climate Events and Disaster Risk Project(Grant 2019QZKK 0104),Sichuan Provincial Department of Science and Technology Project(Grant 2024YFHZ0151) （Grant 2019QZKK 0104）
