大气科学学报2025，Vol.48Issue(1)：152-163,12.DOI:10.13878/j.cnki.dqkxxb.20240212001
三江源层状云系微物理结构特性的飞机观测研究
Microphysical structural characteristics of stratiform clouds over the San-jiangyuan National Nature Reserve:insights from airborne observation
摘要
Abstract
Cold front precipitation cloud systems are the primary target for ecological restoration through artificial precipitation enhancement in the Sanjiangyuan National Nature Reserve.However,the quantitative understanding of these cloud systems remains insufficient.Aircraft observations are currently the only method to directly obtain the phase state of cloud particles,making them a crucial component of cloud and precipitation physics studies.In this study,we analyzed the microphysical characteristics of a typical layered cloud system in the Sanjiangyuan re-gion during spring,based on vertical detection data collected using the particle measurement system(PMS).To discriminate the phase state of cloud particles,the study adopted 2DC image gray projection data,identifying dis-criminate non-spherical cloud particles with sizes between 50 μm and 125 pm as ice crystals.The criteria for phase discrimination included:ⅰ)mean diameter N2(＞50)＞0.1 L-1,and ⅱ)the water content LWCFSSP＞10-3 g/m3.Flight observations revealed a three-layered stratiform cloud system during spring;ⅰ)cirrostratus(Cs)located at an altitude of about 7 400-7 800 m above sea level with a thickness of 300-400 m,consisting entirely of ice-phase clouds,ⅱ)upper and lower layers of altostratus(As)positioned between 6 400-6 600 m above sea level,and 5 100-6 200 m above sea level,respectively.The results show that the high supercooled water regions were primarily distributed in the middle,upper,and lower parts of the low-level As layer.These regions exhibited the highest cloud particle concentrations and supercooled water contents,with distinct regional characteristics.The av-erage cloud particle concentration As measured by FSSP in the studied region was significantly higher than that of stratiform clouds in inland northern China and higher than autumn observation in this region.This regional distinc-tion is largely attributed to the abundant water vapor in the Sanjiangyuan region.The liquid cloud particles in the As layer were predominantly concentrated within a median diameter range of 3.5-27.5 μm,while particles ex-ceeding 30.5 μm were primarily ice-phase.In the middle and upper parts of the low As layer,there was pro-nounced growth in the high supercooled water region,with ice crystal formation and growth predominantly occur-ring in the middle and lower parts.In the low supercooled water regions,the average supercooled water content ra-tio was(90.8％±10.9％).The ratio in the middle to lower parts(95.6％±5.6％)was significantly higher than in the middle and upper parts(79.8％±12.1％).As the primary precipitation-generating cloud layer,accretion growth in the lower As layer was the dominant mechanism for the generation of large-size ice particles.These findings underscore the importance of accurate characterization and understanding of the microphysical structure of the layered cloud system in Sanjiangyuan.Such insights provide a reliable observation basis for the optimizing artificial precipitation enhancement operations in the region.This study has significant practical significance for ad-vancing the understanding of the microphysical characteristics of stratiform clouds in Sanjiangyuan and improving aircraft-based artificial precipitation operation technologies.关键词
三江源/层状云系/飞机观测/机载粒子测量系统(PMS)Key words
Sanjiangyuan National Nature Reserve/stratiform clouds/airborne observations/particle measuring system(PMS)引用本文复制引用
王黎俊,康晓燕,王启花,郭世钰,韩辉邦..三江源层状云系微物理结构特性的飞机观测研究[J].大气科学学报,2025,48(1):152-163,12.基金项目
青海省基础研究计划项目(2020-ZJ-711) （2020-ZJ-711）
第二次青藏高原综合科学考察研究项目(2019QZKK0104) （2019QZKK0104）
