Wind Gust Parameters in the Lower Troposphere Based on Doppler Lidar Data

Abstract

AbstractWind gusts are common small‐scale weather phenomena characterized by a rapid increase in wind speed over a short period of time. Wind gusts affect a wide range of interests, including aviation safety, wind energy and professional skiing, while strong gusts can also cause severe weather events and limit visibility. However, the characteristics of gusts in the lower troposphere are not yet well understood, especially at the top of the boundary layer. In this paper, the gust parameters in the lower atmosphere at different heights and their diurnal variation characteristics are examined based on Doppler lidar data from the gentle coastal topography of Shandong Province, China. The results show that all the gust parameters have distinct stratification characteristics, with significantly different diurnal variations below 400 m, between 400 and 1,200 m, and above 1,200 m (above the ground, same below). Wind gusts are considered to be the result of turbulent disturbances superimposed on the background airflow, and strong turbulence could cause the instantaneous winds to significantly deviate from the mean airflow. The magnitude of the peak gust is mainly controlled by the mean flow, but the gust factor, which is the ratio of the peak gust to the mean flow, is almost independent of the mean flow and has a strong positive correlation with the turbulence intensity. These results imply that gusts of different properties occur at varying altitudes, with differences depending on turbulence intensity and mean airflow, and provide an observational basis for studies of gust structure.