新疆“2.28”大风的中尺度数值模拟

摘要

受西西伯利亚较强冷空气入侵的影响,2007年2月28日02时,乌鲁木齐开往阿克苏的5807次旅客列车,在新疆三十里风区遭遇狂风,造成11节车厢脱轨侧翻。使用WRF模式对这次大风天气过程进行了数值模拟。结果表明：WRF模式较好地模拟了三十里风区大风的演变和分布特征,对逐时风速的模拟较实况偏小,但变化比较同步;很大的气压梯度和特殊的地形是大风形成的主要原因,狭管效应和下坡风同时存在。%At 02：00 BT 28 February 2007,a train of No.5807 from Urumqi to Aksu encountered terrible gale winds,which were caused by northerly cold wave,at the so-called 30 km wind gap in Xinjiang,leading to that the 11 carriages were derailed and overturned.By using mesoscale model WRF,a numerical simulation was made for the gale process.The results show that the WRF can simulate the variation and distribution of the gale in the 30 km wind gap,but the wind velocity of simulation is lower than that of observation, and variation trends of wind velocity are nearly to observations.It may be concluded that the high pressure gradient and special landform are the main reasons of the gale.Meanwhile,both funnel effect and downslope wind also exist.