Abstract:
To explore the wind field detection effect and low-level wind shear identification ability of light detection and ranging (LiDAR) during a wet downburst, a typical wet downburst storm process on 2021-05-18 was analyzed and investigated by using wind LiDAR and meteorological observation records from Xining Caojiapu International Airport, and using the method of combining multiple data with specific events for theoretical analysis and data validation. The results show that the downburst has complex wind field structures. Before the downburst arrived at the airport, the downdraft outflow exceeded 14 m/s, which is coupled with the ambient wind to form a headwind shear convergence line, and the strongest outflow region is located 1 km to 2 km behind the convergence line. When the downburst arrives over the runway, it creates a divergence wind field on the ground. The wind speed in the center of the divergence area is much lower than that at the edge of the outflow, the vertical airflow had drastic changes, and the downburst lasted for about 10 min. The LiDAR has a good identification of the vertical airflow distribution inside the cumulonimbus, the fine structure of the divergence wind field, and the formation and evolution of the convergence line. The interactive use of different detection patterns and data products of LiDAR is very conducive to monitoring and warning of low-level wind shear at the airport. This study provides a reference for the application of LiDAR in the prediction and research of downburst wind shear.