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首页> 外文期刊>Dynamics of Atmospheres and Oceans >A review of ground-based, mobile, W-band Doppler-radar observations of tornadoes and dust devils
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A review of ground-based, mobile, W-band Doppler-radar observations of tornadoes and dust devils

机译：龙卷风和尘暴的地面，移动，W波段多普勒雷达观测综述

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A ground-based, mobile, W-band Doppler-radar has been used in the U.S. during the last decade to obtain high-spatial resolution maps of the radar reflectivity and wind fields in tornadoes and dust devils. This radar is one of the best tools available for studying the substructure of intense, small-scale vortices in the boundary layer. The most significant findings to date are summarized. In one case, it was found that just prior to tornadogenesis in a supercell, a 100-200 m scale cyclonic vortex formed at the leading edge of a bulge in the rear-flank gust front. This vortex appeared to interact with a larger-scale (500 m to 1 km wide) cyclonic vortex, just as the tornado formed. Other small-scale cyclonic vortices were present along the rear-flank gust, but they did not develop into tornadoes. The mature tornado-vortex was dominated by quasi-stationary wavenumber-two disturbances, while the mean vortex resembled a two-celled, Rankine combined vortex. The diameter of the mean vortex narrowed as it intensified and widened as it weakened, even though the tornado condensation funnel narrowed as the tornado was dissipating. Evidence was also found of short-term, inertial-like oscillations in vortex diameter and intensity. Spiral bands and eyes were ubiquitous. The eye in one well-documented case was broader in the lowest few hundred meters than it was aloft. Multiple vortices and "umbilical" cords of very narrow bands of reflectivity have also been found. Both cyclonic and anticyclonic dust devils have been documented. Some dust devils resemble a relatively narrow, Rankine combined vortex, while others are wider and have a broad, calm eye and a narrow annulus of intense vorticity just within the radius of maximum wind (RMW), and rising motion just inside the RMW and sinking motion well inside the RMW. Multiple-vortex structure, Rossby-like wave motion, and the Fujiwhara effect have also been documented.
机译：在过去的十年中，地面移动的W波段多普勒雷达已在美国用于获取龙卷风和沙尘暴中雷达反射率和风场的高空间分辨率图。该雷达是研究边界层强小尺度涡旋子结构的最佳工具之一。总结了迄今为止最重要的发现。在一种情况下，发现在超级细胞中发生龙卷风之前，在后侧阵风前部的凸起前缘形成了一个100-200 m规模的旋风涡。就像龙卷风形成一样，这个旋涡似乎与更大范围（500 m至1 km宽）的旋风涡旋相互作用。在后侧阵风中还存在其他小型旋风涡旋，但它们并未发展成龙卷风。成熟的龙卷风涡旋主要由准平稳波数二扰动控制，而平均涡旋类似于两细胞的兰金联合涡旋。即使龙卷风凝结漏斗随着龙卷风的消散而变窄，但平均涡旋的直径却随着其变大而变窄而变窄。还发现了涡旋直径和强度的类似于惯性的短期振荡。螺旋带和眼睛无处不在。在一个有据可查的案例中，眼下最低的几百米处的眼睛比高处更宽。还发现了反射率很窄的多个涡流和“脐带”。旋风和反旋风尘鬼都已被记录在案。一些尘埃鬼像相对较窄的朗肯混合涡，而另一些尘埃更宽，眼神宽阔而平静，在最大风（RMW）半径内狭窄的环形涡旋，而在RMW内部和下沉处上升运动在RMW内部运动良好。还记录了多涡结构，类似Rossby的波动和藤原效应。

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