四川盆地一次飞机积冰的云微物理特征研究

A Case Study of Microphysical Properties in Aircraft Icing in Sichuan Basin

飞机积冰严重威胁飞行安全,其形成受到云中微物理特征及过程的影响和制约,因此研究积冰的微物理环境有重要的意义。利用DMT公司生产的机载粒子探测设备,计算探测的云粒子数浓度、平均体积直径和液水含量等物理量,分析2015年12月13日四川盆地的一次飞机积冰云系的微物理特征。结果表明:云系可分为3层,其中上层云和中层云的过冷水含量丰富,分别超过0.1 g/m^(3)和0.25 g/m^(3),上层云云滴数浓度大,云滴较小,中层云云滴数浓度较小,云滴较大;积冰发生的高度上,过冷水含量丰富,但随时间变化较大,最大值超过0.35 g/m^(3),冰晶浓度较低,有利于过冷水的维持。

Aircraft icing accumulation is a serious threat to flight safety,and its formation is influenced and constrained by microphysical features and processes in clouds,so it is important to study the microphysical environment of ice accumulation.Using airborne particle detection equipment produced by DMT,physical quantities such as detected cloud particle number concentration,average volume diameter and liquid water content were calculated to analyze the microphysical characteristics of an aircraft cumulus cloud system in the Sichuan Basin on December 13,2015.The results show that the cloud system can be divided into three layers,among which the upper and middle clouds are rich in supercooled water content,exceeding 0.1 g/m^(3)and 0.25 g/m^(3),respectively,with large cloud droplet number concentration and smaller cloud droplets in the upper layer and smaller cloud droplet number concentration and larger cloud droplets in the middle layer.Ice accumulation occurs at heights where supercooled water is abundant but varies greatly with time,with a maximum value of more than 0.35 g/m^(3)and a low concentration of ice crystals,which is conducive to the maintenance of supercooled water.