Transitions between blocked and zonal flows in a rotating annulus with topography
Transitions between blocked and zonal flows in a rotating annulus with topography
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具有地形的旋转环空中阻塞流和纬向流之间的过渡
DOI：
10.1126/science.278.5343.1598
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发表时间：
1997
期刊：
影响因子：
56.9
通讯作者：
Michael Ghil
中科院分区：
文献类型：
--
作者：
Eric R. Weeks;Yudong Tian;J. S. Urbach;J. S. Urbach;Kayo Ide;H. Swinney;Michael Ghil
中纬度的大气以西风为主，接近纬向气流。偶尔，这股气流会被持续10天或更长时间的阻塞反气旋转向极地。在旋转环空中，利用径向抽气在科里奥利力的作用下产生带状射流。在环底部存在两个对称的脊时，产生的气流在高强迫下几乎是纬向的，在低强迫下则被阻塞。由于急流与地形的相互作用，阻塞型和纬向型之间会发生间歇性的转换。这些结果进一步阐明了以前的大气观测和数值模拟。
The mid-latitude atmosphere is dominated by westerly, nearly zonal flow. Occasionally, this flow is deflected poleward by blocking anticyclones that persist for 10 days or longer. Experiments in a rotating annulus used radial pumping to generate a zonal jet under the action of the Coriolis force. In the presence of two symmetric ridges at the bottom of the annulus, the resulting flows were nearly zonal at high forcing or blocked at low forcing. Intermittent switching between blocked and zonal patterns occurs because of the jet's interaction with the topography. These results shed further light on previous atmospheric observations and numerical simulations.