颠覆列车强风数值模式参数敏感性对比分析

Contrast Analysis of Numerical Parameters' Sensitivity in Train-Overthrowing Gale Simulation

新疆的三十里风区是著名的风口,兰新线和南疆铁路线横穿此地,时有列车被强风颠覆,对铁路运输影响很大,急需大风精细预报。数值模式中有许多参数,如何确定改进预报最显著的参数是个问题。采用MM5V3模式做模拟实验,设计3重嵌套,最小格距3km,用30″数字高程数据生成模式地形。分析表明,3km格距模式分辨率对地形有较为精确的表达。无论东西剖面还是南北剖面,3km所预报的风场更为详细,风速预报更准确;不仅可以预报出强的下坡风,亦可以预报出地形波列。对强风预报而言,模式水平分辨率是一个敏感因子。

Accurate forecast of gales is badly needed in the Sanshili Wind Area of Xinjiang,a famous wind area for its so extremely strong wind that the trains passing by are frequently overthrown.A study on numerical parameters＇sensitivity of the MM5V3 model has been conducted with designed 3 nested domains（3 km,9 km,and 27 km）and based on the 30″-DEM（digital elevation model）.The simulation results show that the resolution of 3-km is capable of describing topography precisely,and the wind field with3-km grid resolution is more detailed and the simulated wind speed is more precise as well.Therefore,the horizontal resolution of models is a sensitive factor for gale prediction.