基于1.55μm激光雷达的晴空风切变结构研究

Study on clear sky wind shear structure based on 1.55μmLiDAR

晴空风切变是公认的航空危险天气。为了研究155μm激光测风雷达对晴空风切变的探测效果,利用激光测风雷达数据,结合自观系统实时风场数据,对2022年2月13日影响银川机场的晴空风切变过程进行详细分析。激光雷达探测结果表明风切变发生前高空偏北风有下沉特征,动量下传导致地面北风增强;此次风切变由东北风与西南风交汇形成,东北大风呈楔形从近地层嵌入,形成水平风切变,随后向西南传播影响机场跑道。预报员利用激光测风雷达可以提前15min对此次风切变进行预警。

Clear sky wind shear is a recognized dangerous weather for aviation.To study the detection effect of 1.55μmwind LiDAR for clear sky wind shear,the data from wind LiDAR,combined with real time wind field data from automatic observation system are used to analyze in detail the clear sky wind shear process that affected Yinchuan Airport on February 13th,2022.The results show that the upper air northerly wind has a characteristic of subsidence before wind shear occurs and the momentum is transmitted downward resulting in the increase of surface wind.The northeast gale embeds from surface layer as a shape of wedge,forming a horizontal wind shear which is caused by the convergence of northeasterly and southwesterly winds.Then,the wind shear moves southwestward affecting the airport runway.By using the wind LiDAR,forecaster can give an early warning for this wind shear up to 15 minutes in advance.