利用激光雷达判别机场晴空风切变事件成因

为了研究高原机场的风切变特征,本文利用丽江机场自动观测站资料、NCEP再分析资料,引入三维激光雷达测风资料,对丽江机场2020年3月29日晴空低空风切变特征进行分析。结果表明,此次低空风切变过程主要是受地面变压风辐合、地面增温湍流加强以及动量下传等因素共同影响而形成的。风切变发生期间低空环境风场与地面风场变化基本吻合。5次低空风切变事件中,出现在11:00-12:20风向转变期间的2次风切变为侧风风向切变,出现在12:20-14:20风速逐渐增大期间的3次风切变为风速切变。风切变指数均大于0.1(1/s),切变强度为中度及以上,严重影响飞行安全。研究结果为机场风切变的激光测风雷达监测预警提供了参考依据。

Causal Analysis of a Clear Sky Wind Shear Event at a Plateau Airport in Southwest China Using Lidar Data

In order to study the wind shear characteristics over a plateau airport, this paper uses the data from the Lijiang Airport Automated Weather Observing System (AWOS) and NCEP reanalysis data, as well as 3D data obtained from a wind lidar, to analyze the low level wind shear characteristics of Lijiang Airport on 29 March 2020. The results show that the low level wind shear was mainly formed by the effects of the convergence of the surface isallobaric wind and the enhancement of the turbulence caused by surface warming, as well as the downward momentum transfer. During the occurrence of the wind shear, the low level wind field obtained from the wind lidar was agreed with the surface wind very well. Among the five low level wind shear events, two of them occurred during the orographic wind direction change period from 11:00 to 12:20, and these two are classified as the direction shear of crosswind; the other three occurred from 12:20 to 14:20, which matched with the gradually increasing period of wind speed, and these three are classified as wind speed shear. The wind shear indexes of these five wind shear processes were all greater than 0.1 (1/s), and the shear strengths were moderate or severe, which seriously affected flight safety. The research results provide a reference basis for the laser wind measurement radar monitoring and early warning of airport wind shear.