Case Studies of a Convective Plume and a Dust Devil
Case Studies of a Convective Plume and a Dust Devil
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对流羽流和尘暴的案例研究
DOI：
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发表时间：
1970
期刊：
影响因子：
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通讯作者：
J. Businger
中科院分区：
文献类型：
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作者：
J. Kaimal;J. Businger
摘要 本文通过在堪萨斯州平坦均匀地点上方 5.66 和 22.6 m 处进行的测量，描述了对流羽流和尘暴的特征。使用连续波三分量声波风速计测量速度波动，并使用细铂丝温度计测量温度波动。数据显示羽流基本上是一个非旋转系统；它比沙尘暴更向顺风方向倾斜，其行进速度低于 0.5 m 的平均风速，并且需要垂直拉伸才能在存在风切变的情况下维持其状态。沙尘暴在中部呈现下沉气流，其行进速度高于 32 m 处的平均风速，其稳定性很大程度上来自于旋转。两个系统都倾向于逆着速度梯度向上传输动量，这可能解释了在不稳定条件下观察到的非常低的应力，有时甚至是负应力。
Abstract The paper describes the characteristics of a convective plume and a dust devil from measurements made at 5.66 and 22.6 m above a flat uniform site in Kansas. The velocity fluctuations were measured with a continuous-wave, three-component sonic anemometer and the temperature fluctuations with a fine platinum wire thermometer. The data show that the plume is basically a non-rotating system; it is more tilted in the downwind direction than the dust devil, travels at a lower velocity than the mean wind speed at 0.5 m, and requires vertical stretching for its maintenance in the presence of wind shear. The dust devil shows a down-draft in the middle, travels at a higher velocity than the mean wind at 32 m, and derives much of its stability from rotation. Both systems tend to transport momentum upward, against the velocity gradient, which probably accounts for the very low and sometimes negative stresses observed during unstable conditions.