新疆“2.28”大风过程中热、动力作用的模拟分析

Simulation and Analysis of the Thermal-dynamics Characteristics of "2.28" Severe Wind Event in Xinjiang with WRF Model

对发生在2007年2月27—28日新疆的一次大风天气过程使用WRF模式进行了模拟分析。结果表明,除直接影响天气系统和地形作用外,大风过程中的大气的斜压性产生的垂直速度,使得高空的动量向下传输,是大风形成的原因之一;而局地非绝热加热中的感热和潜热通量的增加,加强近地层的湍流运动,进一步增加了大气的不稳定性,同时和冷锋后部的冷空气形成较强的气压梯度,是此次大风形成的主要的物理机制。

In this paper,a severe wind event in Xinjiang on February 27—28,2007 is simulated and analyzed by the use of the WRF model.The results showed that in addition to impact of weather systems and terrain,the downward momentum transmission of high-level caused by the vertical motion of baroclinic drives is a dynamical factor for the formation of the strong wind;The local adiabatic heating,the increase of sensible heat and latent heat flux,the turbulent above surface layer increasing the instability of atmosphere and producing a strong pressure gradient,and strong cold mass behind the cold front,were the main physical mechanism of the strong wind.