资源环境科技发展态势分析平台

Raindrop size distribution (DSD) characteristics at various altitudes in two landfalling typhoons in 2017 (Hato and Pakhar) were investigated by using laser-optical disdrometers mounted at four altitudes (10, 40, 160, and 320 m) of the Shenzhen 356-m meteorological tower. Significant differences of the DSD and derived parameters, mass-weighted mean diameter (D_m), normalized intercept parameter (N_W), and standard deviation of the mass distribution σ_m, were observed at different altitudes for the two typhoons, while the rainwater content between the four altitudes had no statistically significant differences. The low-altitude DSDs had more midsize drops (1 < D < 3 mm), fewer large drops (D > 3 mm), and narrower distribution widths than the high-altitude ones, while the concentration of small drops varied nonlinearly with height. The value of N_W decreased with height, while D_m and σ_m increased with height. The gamma distribution parameters N₀, μ, and Λ are found to increase with decreasing height. Both the derived μ–Λ and Z–R relations were significantly varied in different altitudes.