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为揭示兰新铁路百里风区大风的形成机制,利用兰新铁路百里风区及周边5个气象站的日极大风速观测数据,分析百里风区极大风的风速、风向时空分布特征及规律;结合地形地貌,着重分析冷空气爬坡翻山现象及下坡地形的加速作用。百里风区十三间房气象站测到的多年平均日极大风速为18.7m·s~(-1),显著高于百里风区周边其他四站(5.5~9.1m·s~(-1)),且十三间房的盛行风向为北风和北西北风,也显著不同于其他四站。局地气压梯度的增大是形成兰新铁路百里风区大风的根本原因,其具体表现在:1冷空气东移,因受天山山脉东段的阻挡而积聚,使天山山脉的南北气压梯度提高;2在吐鲁番—哈密盆地,地面因日照受热而使热气流上升,与积聚在天山山脉东段的冷空气相遇后,使吐鲁番—哈密盆地与山脉之间的气压增大;3百里风区及其周边特殊的地形加强了由气压梯度所形成大风的风速。
In order to reveal the formation mechanism of strong winds in the Baili area of Lanzhou-Xinjiang Railway, the daily maximum wind speed data of 5 weather stations in the Baili area and the surrounding areas of the Lan-Xin Railway are used to analyze the spatial and temporal distribution of wind speed and direction And laws; combined with the topography, emphatically analyzes the phenomenon of over-climbing of cold air and the accelerating effect of downhill terrain. The mean annual maximum wind speed measured by thirteen rooms in the Barry area was 18.7m · s ~ (-1), significantly higher than the other four stations around the Baili wind area (5.5 ~ 9.1m · s ~ (-1) -1)), and the thirteen rooms prevailing wind north and northwest wind, but also significantly different from the other four stations. The increase of the local pressure gradient is the fundamental reason for the formation of strong winds in the Baili zone of the Lanzhou-Xinyu Railway. The concrete manifestation is as follows: 1 The cold air moves eastward, which is obstructed by the eastern segment of the Tianshan Mountains so that the north-south pressure gradient 2 In the Turpan-Hami basin, the hot air current rises due to the sunshine heating in the Turpan-Hami basin, increasing the pressure between the Turpan-Hami basin and the mountains after it meets the cold air accumulated in the eastern Tianshan Mountains. The special terrain of the area and its surroundings enhances the wind speed of strong winds formed by the pressure gradient.