Study on the influence of topography on wind shear-numerical simulation based on WRF-CALMET

Abstract. This study focuses on the critical issue of low-altitude wind shear, vital for aircraft safety during takeoff and landing. Using the WRF-CALMET model, we assess the impact of topography on low-level wind shear at Zhongchuan Airport. CALMET outperforms WRF, showing improved simulation accuracy. CALMET's simulation highlights diurnal variations in vertical wind shear, especially pronounced from 13:00 to 24:00. Notably, CALMET indicates 1–2 hazard levels higher wind shear for aircraft operations compared to WRF in a significant area. Terrain sensitivity experiments reveal CALMET's responsiveness to terrain changes during high wind shear periods, with reduced impact at higher altitudes. CALMET's incorporation of kinematic terrain influences, blocking effects, slope flow, and strengthened diversion of near-surface airflow on complex terrain contribute to these findings. This study confirms the efficacy of CALMET in simulating low-altitude wind shear, emphasizing its superiority in capturing terrain influences and reducing the aviation safety threat posed by low-altitude wind shear.